"The Gender Pay Gap: Have Women Gone as Far as They

"The Gender Pay Gap: Have Women Gone As Far As They Can?" by Francine D. Blau and Lawrence M. Kahn
The authors examine trends in the rate and causes of the gender wage gap. Progress in closing the gap waxed and waned across time, with the gap narrowing in the 1980s, increasing in the 1990s, and, again, narrowing in the early 2000s. The causes of the gap appear to be fairly consistent with a combination of human capital and basic socio-demographic factors both playing a role, though their respective roles differ across time.
-The gender wage gap is found:

A) Across selected occupations
B) Across all occupational levels
C) At only a few occupational levels
D) At virtually no occupational levels at the present time.