Mark was a student at this university from 1999 to 2003, ________ he studied very hard and was made Chairman of the Students' Union.

1. A.
   during which time
2. B.
   for which time
3. C.
   during whose time
4. D.
   by that time

Mark was a student at this university from 1999 to 2003, ____ ,  he studied very hard and was made Chairman of the Students' Union.

A. during which time   B. for which time     C. during whose time     D. by that time

Mark was a student at this university from 1999 to 2003, _______he studied very hard and was made chairman of the Students’ Union.

A.during which time                           B.for which time

C.during whose time                           D.by that time

Mark was a student at this university from 1999 to 2003, _______ he studied very hard and was made Chairman of the Students Union.?

A. during which time

B. for which time

C. during whose time

D. by that time?

Mark was a student at this university from 1999 to 2003, ____ ,  he studied very hard and was made Chairman of the Students' Union.

A. during which time   B. for which time     C. during whose time     D. by that time