Many of Psychology's Earliest Pioneers Such as Wilhelm Wundt, William

Many of psychology's earliest pioneers such as Wilhelm Wundt, William James,
Hermann Ebbinghaus, and Edward Titchener, could all be described as cognitive psychologists. But their brand of psychology mostly disappeared in America for a 50-year period because

A) their research methods were found to be inaccurate
B) of the influence of Darwinian ideas that emphasized a focus on learning
C) of the advent and dominance of behaviorism
D) they were too closely tied to philosophical questions