In Spanish, how is gustar conjugated relative to what is liked?

In Spanish, how is gustar conjugated relative to what is liked?

• A. The verb agrees with the thing liked; indirect object pronouns are not used.
• B. The verb agrees with the subject; indirect object pronouns are used.
• C. The verb agrees with the thing liked; indirect object pronouns are used.
• D. The verb agrees with the subject; pronouns are optional.

Answer: (C)