In Which Circumstances Will the Majority of Men and Women

In which circumstances will the majority of men and women be in polygynous marriages (in those societies that allow polygyny) ?

A) when men are heavily involved in productive work for little wealth
B) when women are dependent on men for support
C) when the mean age for females at marriage is well below that of males
D) when women are more valued as childbearers than as labourers