Some Couples Choose the Breadwinner/housewife Arrangement Even When They Have

Some couples choose the breadwinner/housewife arrangement even when they have egalitarian beliefs, often because

A) the alternative of being Super Mom is not practical for women of their social class or race
B) the women have been socialized to accept a move full-time to the second shift and men were socialized to be breadwinners.
C) there is a relatively large difference between what the average husband and wife earns.
D) they know that maintaining care chains helps lower income families.