One Problem Researchers Have Had in Finding Experimental Evidence in Support

Multiple Choice

One problem researchers have had in finding experimental evidence in support of Freud's theory of humor is that

A) many of the findings are subject to alternative explanations.
B) predictions can't be derived from Freud's theory.
C) very few, if any, of the findings have been replicated.
D) researchers are unable to manipulate the participant's unconscious thoughts.