The correct option is D a verb that is combined with an adverb or preposition to obtain a variety of meanings
A phrasal verb is a phrase of the form verb + adverb, verb + preposition or verb + adverb + preposition, option D describes a phrasal verb, hence it's correct. A verb when combined with a noun (if that noun is the object) is a verb phrase. Phrasal verbs and verb phrases are not the same hence option A is incorrect. Verbs that function as nouns are gerunds and infinitives, they're not phrasal verbs, hence option B is incorrect. Verbs don't modify adverbs, but it's the vice versa, and they do not describe phrasal verbs, hence option C is incorrect.