Which term is a lie detector?

Which term is a lie detector?

• A. Lie Detector
• B. Truth Serum
• C. Voice Stress Analyzer
• D. Polygraph

Answer: (D)

A polygraph is the instrument most associated with lie detection. It records several physiological signals—such as heart rate, breathing, blood pressure, and skin conductance—while a person answers questions. The idea is that deceptive responses tend to produce measurable changes in these bodily functions, which the device plots on a chart. This makes it the best fit for a lie detector among the options because it is a specific, operational device used for deception detection. The other terms don’t fit as detectors in the same way. A generic “lie detector” label refers to the concept rather than a specific instrument. A truth serum is a drug, not a device that measures deception, and its ability to reveal truth is unreliable and not considered a true lie detector. A voice stress analyzer claims to detect deception from voice patterns, but its scientific validity is disputed and it’s not widely accepted as a reliable lie-detecting tool.

A polygraph is the instrument most associated with lie detection. It records several physiological signals—such as heart rate, breathing, blood pressure, and skin conductance—while a person answers questions. The idea is that deceptive responses tend to produce measurable changes in these bodily functions, which the device plots on a chart. This makes it the best fit for a lie detector among the options because it is a specific, operational device used for deception detection.

The other terms don’t fit as detectors in the same way. A generic “lie detector” label refers to the concept rather than a specific instrument. A truth serum is a drug, not a device that measures deception, and its ability to reveal truth is unreliable and not considered a true lie detector. A voice stress analyzer claims to detect deception from voice patterns, but its scientific validity is disputed and it’s not widely accepted as a reliable lie-detecting tool.