He asked me if I knew who that girl was.
Which one of the following is the correct Yes - No question corresponding to the sentence above?
(a) Do you know who is that girl?
(b) Did you know who is that girl?
(c) Did you know who that girl was?
(d) Did you ask me who that girl was?
1
(d) only
2
(b) only
3
(c) only
4
(a) only