According to the Text, Which of the Following Has Been

According to the text, which of the following has been a factor in female workforce participation?

A) More men were attending postsecondary schools which opened up positions for women in the workforce.
B) After World War II, women's paid labour became a needed source of family income.
C) Female labour force participation rates for women with very young children declined.
D) Female workers, as part of the war effort, changed the perception and expectations of women.