Read the sentence.

On cold winter days, Mrs. Brown enjoyed snuggling under a blanket near the fire.

Which answer correctly explains the role of the word snuggling in this sentence?

It is an adverb that modifies the verb enjoyed.
It is a verb in the main clause of this sentence.
It is a participle because it is the -ing form of a verb that is functioning as an adjective: it modifies the word blanket.
It is a gerund because it is the -ing form of a verb that is functioning as a noun: it is the object of the verb enjoyed.