A, B, C, D, E and F are six members of a family. There are parents, their children and grandchildren in the family. A is the son of C and E is the daughter of A. D is the daughter of F who is the mother of E. Which of the following pairs is the grandchildren of the parents?

To find the pair of grandchildren in the family, we can analyze the relationships step-by-step:
1. A is the son of C: This means C is a parent of A. C is in the first generation (grandparent/parent level) relative to A.
2. E is the daughter of A: Since A is the son of C and E is the daughter of A, A is a parent of E, and C is the grandparent of E. Thus, E is one of the grandchildren.
3. D is the daughter of F who is the mother of E: We know E's father is A. Since F is the mother of E, A and F must be married (parents of E). D is also the daughter of F (and thus A). Since D and E are both children of A and F, and A's parent is C, both D and E are the children of A and F, making them the grandchildren of C.
4. Thus, the grandchildren of the family are D and E.

Looking at the options, the pair that represents the grandchildren is D, E.