Explanation:

- W is the wife of V, indicating they are a married couple.

- W is also the mother of Z.

- X is the grandmother of U, which means X has a child who is a parent of U.

- X is the mother of V, meaning V is a parent of U, making V and W (being a married couple) the parents of U.

- Z is the granddaughter of Y, meaning Y is a parent of either W or V, but since X, who is V's parent, is already known, Y is most likely W's parent.

- Therefore, W is the mother of U.

- Option 1: Mother is the correct answer, as W is U's mother.