Explanation:

Let’s break this down step by step:

- There are 7 members: S, T, U, V, W, X, and Y. Only 3 are female.

- S is married to V.

- W is V’s grandson. V has two children.

- U is Y’s sister-in-law. Y is unmarried.

- X is S’s brother-in-law, and S is mother-in-law of U.

- If Z is Y’s husband, the question: How is T related to Z?

Let’s piece the relationships together:

- S (female – because she is mother-in-law of U) is married to V.

- V must be male (V has a grandson W).

- S and V have two children.

- W is V’s grandson—so, W is the child of either S and V’s son or daughter.

- X is brother-in-law of S, so he must be V’s brother.

- U is sister-in-law of Y (Y is unmarried at first, then later married to Z), so U must be the wife of either T or X.

- Since S is mother-in-law of U, U must have married S’s son T.

So, S (mother), V (father), T (son), X (uncle), Y (daughter), U (son’s wife), W (grandson), Z (married to Y).

When Y marries Z, Z is S and V’s son-in-law and T is Y’s brother.

So, T is Z’s brother-in-law.

Option 3: Brother-in-Law is correct.