The old lady had two clever sons, ______ did a good job in the 2010 National College Entrance Exam, though.

1. A.
   none of them
2. B.
   both of whom
3. C.
   none of whom
4. D.
   neither of whom

 The old lady had two clever sons, ____ did a good job in the 2010 National College Entrance Exam, though.

   A. none of them       B. both of whom    C. none of whom          D. neither of whom

The old lady had two clever sons, ____ did a good job in the 2010 National College Entrance Exam, though.

 The old lady had two clever sons, ____ did a good job in the 2010 National College Entrance Exam, though.

   A. none of them       B. both of whom    C. none of whom          D. neither of whom