shilapentokh's study indicated that ,in soviet union ,women's absenteeism from their jobs ,despite their home duties and their child-care responsibilities ,were only a fifth of men .
a)were only a fifth of men
b)were only a fifth of men's
c)was only a fifth of men's
d)was only a fifth of men
e)was a fifth of only of that of men
答案是C。
但是GMAT不是不让用A of B's 这样的双重所有格吗?
还是说这里不是双重所有格?