Bettina describes herself as a lesbian and is in a long-term relationship with another woman, whom she recently married. the best biological explanation for bettina's sexual orientation is that there (select one):

a. was greater exposure to androgens while she was in the womb.
b. was an insufficient level of estrogen released during puberty.
c. is an extra y sex chromosome in her dna.
d. is inadequate functioning of her ovaries.