The right answer is A. My sister's most annoying habit is (hopping on the living room couch.)
Answer: The underlined phrase that is the gerund phrase and predicate noun of the sentence is A) My sister's most annoying habit is (hopping on the living room couch.)
Explanation: A gerund phrase is made up of a gerund, that is to say the non-finite form of the verb that ends in -ing, and its modifiers. Moreover, the predicate noun of the sentence, which provides more information about the subject, is only present when there is a linking verb. Furthermore, the predicate noun always comes after the linking verb. In that way, the underlined phrase in A) (hopping on the living room couch) is the gerund phrase and predicate noun as "hopping" is a gerund and "on the living room couch" is a modifier. Moreover, "hopping on the living room couch" has been preceded by the linking verb "is".
