Overall,research Has Found the Effects of Testosterone on the Aggressive

Overall,research has found the effects of testosterone on the aggressive behavior of humans to be inconsistent.The text suggests that this inconsistency may be attributable to the fact that

A) hormones may have less effect on human aggression than they do on aggression in other species.
B) the tests that have been used to study testosterone and aggression in humans are markedly different from those used in other species.
C) testosterone can be synthesized and act locally in particular brain structures, but studies of testosterone and human aggression have been based on general blood levels of testosterone.
D) all of the above
E) both A and B