Here's why:
* Antecedents are the nouns or pronouns that a pronoun refers back to. For example, in the sentence "The cat chased its tail," "cat" is the antecedent of the pronoun "its."
* Interrogative pronouns are used to ask questions. They stand in for the unknown information being sought. Examples include *who, whom, whose, what, which, where, when, why, how*.
Since interrogative pronouns are used to seek information, they don't refer to a previously established noun or pronoun.
Let me know if you have any other questions!