All the Following Are Problems with the Behavioural Approach EXCEPT

All the following are problems with the behavioural approach EXCEPT that

A) there is no evidence that people acquire psychological disorders because of improper conditioning.
B) improvements in a controlled environment such as a lab might not generalize to real-world settings.
C) it is difficult to test empirically.
D) the behaviourist view does not take the complexity of behaviour into account.