Read the following information and answer the questions that follows:
A family consists of six members P, Q, R, S, T and U.There are two married couples. Q is a doctor and the father of T. U is the grandfather of R and is a contractor S is grandmother of T and is a housewife. There is one doctor, one contractor, one nurse, one housewife and two students in the family.

 Who is the sister of T?
(1) R
(2) U
(3) T
(4) Data inadequate

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.

(1) 1 and 2 both are required
(2) Only 2
(3) Either 1 or 2
(4) Only 1