Meaning: 'Sophisticated' refers to something that is complex or advanced in design or function.

Wrong options:

• irrelevant: Irrelevant is an adjective that means not connected or applicable, which does not describe machines.
• clarify: Clarify is a verb meaning to make something clear or easier to understand, which does not fit as a description of machines.
• insignificant: Insignificant is an adjective meaning not important or worthy of attention, which does not appropriately describe advanced machines.
• radical: Radical is an adjective that means relating to or affecting the fundamental nature of something, which does not fit the context of describing machines.

Correct answer: irrelevant

Explanation: The term 'irrelevant' is an adjective that describes questions that do not pertain to the matter at hand. It fits grammatically as it modifies 'questions' and contextually indicates that these questions do not contribute to the assessment of truthfulness.

Meaning: 'Irrelevant' means not related to the subject or situation.

Wrong options:

• clarify: Clarify is a verb that means to make something clear, which does not fit as it does not describe the nature of questions.
• insignificant: Insignificant is an adjective meaning not important, which does not accurately describe the questions in this context.
• sophisticated: Sophisticated is an adjective that describes complexity, which does not apply to the nature of questions being asked.
• radical: Radical is an adjective that refers to fundamental changes, which does not fit the context of describing questions.

Correct answer: identify

Explanation: The verb 'identify' is used here to indicate the action of recognizing or determining the presence of lies. It fits grammatically as it follows 'to' and aligns with the context of the test's purpose.

Meaning: 'Identify' means to recognize or establish the identity of something.

Wrong options:

• clarify: Clarify is a verb that means to make something clear, which does not fit the context of recognizing lies.
• irrelevant: Irrelevant is an adjective that does not fit as it does not describe an action related to detecting lies.
• sophisticated: Sophisticated is an adjective that does not fit as it does not convey an action but rather describes complexity.
• establish: Establish is a verb that means to set up or confirm, which does not fit the context of recognizing lies.

Correct answer: establish

Explanation: The verb 'establish' is used to indicate the action of setting a baseline for comparison. It fits grammatically as it follows 'to' and aligns with the context of the test's procedure.

Meaning: 'Establish' means to set up or create something on a firm or permanent basis.

Wrong options:

• clarify: Clarify is a verb that means to make something clear, which does not fit the context of setting baseline values.
• irrelevant: Irrelevant is an adjective that does not convey an action related to establishing values.
• sophisticated: Sophisticated is an adjective that does not fit as it does not describe an action but rather describes complexity.
• identify: Identify is a verb that means to recognize, which does not fit the context of setting baseline values.