The question is ______ will take care of the children.
A. who
B. that
C. what
D. whether
I doubt______ the train will arrive here on time.
A. what
B. when
C. whether
D. who
I don't care ______ he will apologize to me or not.
A. who
B. whether
C. when
D. how
He asked me_______ told me the accident.
A. whom
B. which
C. who
D. whose