Piaget's Ideas Were Largely Ignored by American Psychologists Until the 1960s

Multiple Choice

Piaget's ideas were largely ignored by American psychologists until the 1960s. Three of the following are probable reasons why this was so. Which one is not a likely reason?

A) Piaget studied children rather than nonhuman species.
B) Piaget's ideas were incompatible with behaviorist theory.
C) Most of Piaget's writings were in French.
D) Piaget used research methods that were unconventional in the eyes of American psychologists.