Who is the brother of C?
P. D is the daughter of M.
Q. M is the father of C.

if the data in statement P alone are sufficient to answer the question, while the data in statement Q alone are not sufficient to answer the question.

if the data in statement Q alone are sufficient to answer the question, while the data in statement P alone are not sufficient to answer the question.

if the data even in both the statement P and Q together are not sufficient to answer the question.

if the data in both statements P and Q together are needed to answer the question.