Of the Following,which Has Contributed Most to the Progressive Lowering

Of the following,which has contributed most to the progressive lowering of the onset of menarche in American women?

A) Older males tend to be attracted to much younger females.
B) Improved health and nutrition lead to earlier maturity.
C) Improved environmental quality and standard of living increases have led to earlier maturity.
D) The gradual increase in minimum wage and financial equity between males and females.