Gerund is one of three kinds of verbals. Like all verbals, gerunds are nouns derived from verbs. Gerunds end in -ing. In the sentence, "leading" is the gerund. This gerund phrase is used as the direct object.
A geruns is a verb in the <em>-ing</em> form which functions as a noun. In the sentence given, the gerund phrase works as a direct object of the verb <em>enjoy</em>. 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 <em>be</em>, and the gerund phrase does not function as the subject in this sentence.
