A study of labor force participation rates of women in the post-World War II period noted:

Over the long run, women have joined the paid labor force because of a series of changes affecting the nature of work. Primary among these was: 

A.) the rise of the clerical and professional sectors, 

B.)the increased education of women, 

C.)labor-saving advances in households, 

D.)declining fertility rates, and 

E.) increased urbanization. 

Relate each of these factors to the household production model of labor supply.