Although the Median Income of American Families Stagnated from 1970s

Although the median income of American families stagnated from 1970s to 1990, the reason it didn't decline was

A) people logged more hours.
B) the rise in wages of working married men and women exceeded the rate of inflation.
C) wives' wages maintained the family income.
D) people had fewer children.
E) All of these choices are correct.