Which of the Following Aspects of Freud's Theory Has Been

Which of the following aspects of Freud's theory has been challenged by new research?

A) the identification of feeding, toilet training, and early sexual experiences as critical events in personality formation
B) his proposition that development proceeds through a series of stages
C) his idea that the first years of life help shape adult personality
D) his portrayal of the elementary school years as free from sexuality and unimportant for personality development