Ans:D. PolygraphA polygraph, popularly referred to as a lie detector test, is a device or procedure that measures and records several physiological indicators such as blood pressure, pulse, respiration, and skin conductivity while a person is asked and answers a series of questions.The belief underpinning the use of the polygraph is that deceptive answers will produce physiological responses that can be differentiated from those associated with non-deceptive answersUS law enforcement and federal government agencies such as the FBI, NSA and the CIA and many police depaments such as the LAPD and the Virginia State Police use polygraph examinations to interrogate suspects and screen new employee