Which provides the best description of the underlined phrase?

roger, a hot-tempered football player, charged the referee and tried to tackle the poor man.
a) a verb form that is used as an adjective to describe roger
b) a noun phrase that functions as the subject of the sentence
c) a verb form that is used as an adverb to explain roger's behavior
eliminate
d) an appositive phrase that describes another noun or pronoun in the sentence

a hot-tempered football player is underlined