What Aspect of Kohlberg's Cognitive-Developmental Theory of Gender-Typing Has not

What aspect of Kohlberg's cognitive-developmental theory of gender-typing has not received support?

A) the view that a mature understanding of gender is necessary for gender-typing
B) the view that understanding of gender is related to cognitive development
C) the view that there are stages of gender identity development
D) the view that children with more mature gender concepts tend to seek out and attend to same-sex models
E) the view that a mature understanding of gender is necessary for gender-typing and the view that children with more mature gender concepts tend to seek out and attend to same-sex models