Question

Which sentence contains the interrogative pronoun?

A.
The house, which the family had owned for years, had to be sold.

B.
There are the glasses I’ve been looking for.

C.
What did you say when you found out that you had won?

D.
Isabel herself wishes to thank the members of the academy

Answer 1

It should be C. because interrogative pronouns are used to ask questions. 

Answer 2

C.

What did you say when you found out that you had won?

Step-by-step explanation:

The five interrogative pronouns are what, which, who, whom, and whose.

Interrogative pronouns can also be used as relative pronouns, which may be found in questions or indirect questions. That is the case of sentence A

A.

The house, which the family had owned for years, had to be sold