In Your Role as a Psychological Consultant, You Are Advising

In your role as a psychological consultant, you are advising Canadian Customs officials on border checks. They are interested in increasing the ability of border guards to detect facial expressions of emotion. What one piece of advice might be most useful?

A) use female border guards
B) have the guards in a low state of arousal
C) tell the guards to not be empathetic
D) use male border guards
E) have the guards in a high state of arousal