What Is Believed to Be the Cause of the Birth

Multiple Choice

What is believed to be the cause of the birth order effect (i.e., the observation that homosexual boys tend to be later in birth order than heterosexual boys) ?

A) A maternal immune reaction that lessens the impact of male androgens prenatally
B) Socialization affects that result in these boys being treated in a more feminine manner
C) Higher activity levels of first-borns versus later borns
D) None of the alternatives are correct.