Correct option is C
A polygraph, commonly known as a lie detector, is an instrument that measures and records several physiological indicators such as blood pressure, pulse, respiration, and skin conductivity while a person is asked a series of questions. The belief is that deceptive answers will produce physiological responses that can be differentiated from those associated with non-deceptive answers. While polygraphs are commonly used in criminal investigations and security screenings, their accuracy and reliability have been debated, with critics arguing that physiological responses can be triggered by anxiety or nervousness unrelated to deception. Despite this, polygraphs continue to be used in various fields.
