Freud's Theory About People Fixated at the Anal Stage Becoming

Freud's theory about people fixated at the anal stage becoming stubborn and regulating:

A) is related to Freud's theory that those fixated at the oral stage become strict and inflexible.
B) has a lot of backing by current personality research.
C) is unsupported by current research in personality theory.
D) was an important factor in the humanistic movement.