Answer: A. her/him
"Her" and "him" are the singular, object pronouns of the third person (in contrast with "she" and "he," which are the singular, subject pronouns of the third person). These pronouns are used when describing the object of the verb. Most of the time, this means that they are placed after the verb that modifies them. In this case, both sentences use the verb "is," and they both place the person as the object of the sentence. Therefore, "her" and "him" are the correct choices.