Meaning: 'Matter' refers to the physical substance or material, particularly in a biological context.

Wrong options:

• subtle: The word 'subtle' is an adjective that describes something delicate or understated, which does not fit as it does not refer to a physical substance.
• established: The word 'established' is a verb that does not fit grammatically as it does not refer to a noun or substance.
• therapeutic: The word 'therapeutic' is an adjective that describes something related to healing, which does not fit as it does not refer to a substance.
• action: The word 'action' is a noun that refers to the process of doing something, which does not fit as it does not refer to a substance.
• infection: The word 'infection' is a noun that refers to the invasion of the body by harmful organisms, which does not fit as it does not refer to a substance.
• culture: The word 'culture' is a noun that refers to the cultivation of microorganisms, which does not fit as it does not refer to a substance.
• collection: The word 'collection' is a noun that refers to a group of items gathered together, which does not fit as it does not refer to a substance.

Correct answer: infection

Explanation: The term 'infection' is a noun that refers to the invasion of the body by pathogenic microorganisms. It fits contextually as it describes what the preparations were intended to destroy.

Meaning: 'Infection' refers to the process of being infected by harmful microorganisms.

Wrong options:

• subtle: The word 'subtle' is an adjective that does not relate to a harmful condition and does not fit in this context.
• matter: The word 'matter' refers to physical substance and does not fit as it does not describe a harmful condition.
• established: The word 'established' is a verb that does not fit as it does not describe a harmful condition.
• action: The word 'action' is a noun that refers to the process of doing something, which does not fit as it does not describe a harmful condition.
• capable: The word 'capable' is an adjective that describes ability, which does not fit as it does not describe a harmful condition.
• culture: The word 'culture' refers to the cultivation of microorganisms and does not fit as it does not describe a harmful condition.
• collection: The word 'collection' refers to a group of items gathered together and does not fit as it does not describe a harmful condition.

Correct answer: capable

Explanation: The word 'capable' is an adjective that describes the ability of a microorganism to perform an action, in this case, destroying another species. It fits grammatically and contextually in the sentence.

Meaning: 'Capable' means having the ability or capacity to do something.

Wrong options:

• subtle: The word 'subtle' is an adjective that describes something delicate or understated, which does not fit as it does not describe ability.
• matter: The word 'matter' is a noun that refers to physical substance and does not fit as it does not describe ability.
• established: The word 'established' is a verb that does not fit as it does not describe ability.
• action: The word 'action' is a noun that refers to the process of doing something, which does not fit as it does not describe ability.
• infection: The word 'infection' is a noun that refers to a harmful condition and does not fit as it does not describe ability.
• culture: The word 'culture' refers to the cultivation of microorganisms and does not fit as it does not describe ability.
• collection: The word 'collection' refers to a group of items gathered together and does not fit as it does not describe ability.

Correct answer: established

Explanation: The word 'established' is a verb that indicates that something has been proven or recognized. It fits grammatically and contextually as it describes the recognition of the microorganism's ability to destroy another species.

Meaning: 'Established' means to have been proven or recognized as valid or true.

Wrong options:

• subtle: The word 'subtle' is an adjective that does not fit as it does not convey the idea of recognition or proof.
• matter: The word 'matter' is a noun that does not fit as it does not convey the idea of recognition or proof.
• capable: The word 'capable' is an adjective that describes ability but does not fit as it does not convey the idea of recognition or proof.
• action: The word 'action' is a noun that refers to the process of doing something, which does not fit as it does not convey the idea of recognition or proof.
• infection: The word 'infection' is a noun that refers to a harmful condition and does not fit as it does not convey the idea of recognition or proof.
• culture: The word 'culture' refers to the cultivation of microorganisms and does not fit as it does not convey the idea of recognition or proof.
• collection: The word 'collection' refers to a group of items gathered together and does not fit as it does not convey the idea of recognition or proof.

Correct answer: therapeutic

Explanation: The word 'therapeutic' is an adjective that describes something related to healing or treatment. It fits contextually as it describes the intended use of the action noted by Pasteur.

Meaning: 'Therapeutic' refers to something that has healing properties or is used for treatment.

Wrong options:

• subtle: The word 'subtle' is an adjective that describes something delicate or understated, which does not fit as it does not relate to healing.
• matter: The word 'matter' is a noun that refers to physical substance and does not fit as it does not relate to healing.
• established: The word 'established' is a verb that does not fit as it does not describe a use related to healing.
• action: The word 'action' is a noun that refers to the process of doing something, which does not fit as it does not describe a use related to healing.
• infection: The word 'infection' refers to a harmful condition and does not fit as it does not describe a use related to healing.
• culture: The word 'culture' refers to the cultivation of microorganisms and does not fit as it does not describe a use related to healing.
• collection: The word 'collection' refers to a group of items gathered together and does not fit as it does not describe a use related to healing.