Recent research shows that hesitation, shifting posture, and failure to maintain eye contact are not reliable indicators in discriminating between those who are lying and those who are telling the truth. The research indicates that behavior that cannot be controlled is a much better clue, at least when the lie is important to the liar. Such behavior includes the dilation of eye pupils, which indicates emotional arousal, and small movements of facial muscles, which indicate distress, fear, or anger. Which one of the following provides the strongest reason for exercising caution when relying on the "better" clues mentioned above in order to discover whether someone is lying? ['A person telling the truth might be affected emotionally by being suspected of lying or by some other aspect of the situation.', 'A person who is lying might be aware that he or she is being closely observed for indications of lying.', 'Someone who is telling the truth might nevertheless have a past history of lying.', 'A practiced liar might have achieved great control over body posture and eye contact.']