|A) Sister and Brother||B) Mother and Son|
|C) Grandmother and Grand daughter||D) Sisters|
E is the daughter of A and F is the mother of E. So, A is the father of E and hence the husband of F. Now,
D is the daughter of F. So, D and E are the daughters of A and F Also. A is the son of C.
Now, only B remains. Thus, B and C are the parents of A.
Clearly. D and E are sisters