Why Did the Proportion of Women Working as Secretaries and Sales

Why did the proportion of women working as secretaries and sales clerks increase in the late nineteenth and early twentieth centuries?

A) These jobs were attractive to women because they offered better working conditions and higher status
B) Managers in department stores considered female cashiers to be much more trustworthy that male cashiers
C) Sales jobs demanded many different skills that women usually possessed
D) Sales jobs usually led to the managerial positions that most working women desired