It is well established that certain autonomic responses such as heart rate, perspiration, and respiration change under stress. in view of the fact that people generally have stronger autonomic responses when lying than when telling the truth, it follows that the polygraph would be a foolproof approach to lie detection.
which statement best explains why the polygraph is not more widely used in courtrooms and in testing of job applicants?

a) most people can avoid detection when they lie.
b) physiological arousal is much the same for several emotions, so the polygraph cannot always reliably distinguish guilt from other reactions.
c) a significant number of people show paradoxical autonomic reactions, responding more strongly when telling the truth than when lying.
d) in controlled studies, the polygraph has correctly identified guilty individuals in only a small percentage of cases.
e) the polygraph has been shown to be reliable only in highly emotional cases, such as child abuse and spying.