Answer:
D. gerund phrase as a direct object
Step-by-step explanation:
A geruns is a verb in the -ing form which functions as a noun. In the sentence given, the gerund phrase works as a direct object of the verb enjoy. As a result, it receives the action if the verb.
The rest of the options are incorrect because participial phrases work as adjectives, a predicate noun indicates a state and follows a linking verb like be, and the gerund phrase does not function as the subject in this sentence.