The answer would be gusta.
The verb gustar is different from other verbs, because it isn't conjugated according to the pronoun, instead it is conjugated according to the noun. For example, in this sentence <em>Nos </em>is plural, but <em>la tele </em>is singular and therefore gustar is conjugated in the singular version
Here is an example sentence:
A ella le _____ las galletas
The blank would be <em>gustan</em>. Even though <em>she </em>is singular the <em>cookies </em>are not and gustar would be plural.
Hope this helped!