If D is the brother of B, how B is related to C? To answer this question which of the statements is/are necessary? 1. The son of D is the grandson of C. 2. B is the sister of D.

The correct answer is: C. Either 1 or 2.

Statement 1: The son of D is the grandson of C.

This statement tells us that D is a father, and C is a grandfather. This means that D and C are related in some way, and that D is older than C. However, it does not tell us how D and C are related. D could be C’s son, C’s grandson, C’s nephew, or C’s cousin.

Statement 2: B is the sister of D.

This statement tells us that B and D are siblings. This means that they have the same parents. This also means that B and C are related, because they have a child in common. However, it does not tell us how B and C are related. B could be C’s daughter, C’s granddaughter, C’s niece, or C’s cousin.

In order to determine how B is related to C, we need more information. Either statement 1 or statement 2 is sufficient to determine that B is related to C, but neither statement is necessary.