Answer:
The correct answer is B. verbal phrase.
Explanation:
A verbal phrase has to contain some kind of a verbal - be it a participle, a gerund, or in this case, an infinitive. The phrase contains an infinitive to listen, and given that infinitives are verbals, the entire phrase is a verbal phrase.
Prepositional phrases start with a preposition.
Appositive phrases are separated by commas.
Absolute phrases can be deleted from the sentence without changing its meaning.
