Meaning: Endorphins are hormones produced by the body that help relieve pain and induce feelings of pleasure or euphoria.

Wrong options:

• ecological: 'Ecological' is an adjective relating to the environment, which does not fit the context of hormones related to mood.
• confidence: 'Confidence' is a noun that refers to self-assurance, but it does not relate to hormones released during exercise.
• self-esteem: 'Self-esteem' is a noun that refers to one's sense of self-worth, which is not a hormone and does not fit here.
• mental: 'Mental' is an adjective that describes something related to the mind, but it does not refer to a specific hormone.
• neurological: 'Neurological' is an adjective that pertains to the nervous system, which does not fit as a noun in this context.

Correct answer: neurological

Explanation: The word 'neurological' is an adjective that describes the functioning of the nervous system. It fits grammatically as it modifies the noun 'functioning' and contextually aligns with the discussion about exercise enhancing cognitive abilities.

Meaning: Neurological refers to anything related to the nervous system, particularly in terms of its functions and health.

Wrong options:

• ecological: 'Ecological' is an adjective related to the environment, which does not pertain to brain or nervous system functions.
• endorphins: 'Endorphins' is a plural noun referring to hormones, which does not fit as an adjective describing functioning.
• confidence: 'Confidence' is a noun that does not describe a type of functioning and is unrelated to the context of neurological health.
• self-esteem: 'Self-esteem' is a noun that refers to one's self-worth, which does not fit as a descriptor for functioning.
• mental: 'Mental' is an adjective that could relate to cognitive functions but is less specific than 'neurological' in this context.
• accomplishment: 'Accomplishment' is a noun that refers to achieving something, which does not fit as a descriptor for functioning.

Correct answer: confidence

Explanation: The term 'confidence' is a noun that fits grammatically as it describes how individuals feel about themselves. Contextually, it aligns with the positive effects of regular exercise on self-perception and self-assurance.

Meaning: Confidence refers to a feeling of self-assurance arising from one's abilities or qualities.

Wrong options:

• ecological: 'Ecological' is an adjective that does not relate to personal feelings or self-perception.
• endorphins: 'Endorphins' is a noun referring to hormones, which does not fit as a descriptor of personal feelings.
• self-esteem: 'Self-esteem' is a noun that relates to self-worth, which is similar but does not fit the context of feeling about oneself in this specific phrasing.
• mental: 'Mental' is an adjective that does not describe a feeling or state of being, making it unsuitable here.
• neurological: 'Neurological' is an adjective that pertains to the nervous system and does not relate to personal feelings or self-assurance.
• accomplishment: 'Accomplishment' is a noun that refers to achieving something, which does not fit as a descriptor of how individuals feel about themselves.

Correct answer: accomplishment

Explanation: The word 'accomplishment' is a noun that fits grammatically as it describes a sense of achievement. Contextually, it aligns with the idea that maintaining a workout schedule leads to feelings of success and personal achievement.

Meaning: Accomplishment refers to something that has been achieved successfully, often through effort.

Wrong options:

• ecological: 'Ecological' is an adjective that does not relate to personal achievements or feelings of success.
• endorphins: 'Endorphins' is a noun referring to hormones, which does not fit as a descriptor of personal achievement.
• confidence: 'Confidence' is a noun that refers to self-assurance, which does not fit the context of a sense of achievement in this phrasing.
• self-esteem: 'Self-esteem' is a noun that refers to one's sense of self-worth, which does not fit as a descriptor of achievement.
• mental: 'Mental' is an adjective that does not describe a sense of achievement and is unsuitable here.
• neurological: 'Neurological' is an adjective that pertains to the nervous system and does not relate to personal accomplishments.