Which answer choice best explains how the bolded participial phrase is used in this sentence?
Thinking it was after eight o'clock, Sam hurried home.
(A) It is used as a verb to name the main action of the sentence.
(B) It is used as an adverb to describe the verb hurried.
(C) It is used as a noun and acts as the subject of the sentence.
(D) It is used as an adjective to describe the noun, Sam.