Which part of speech is the underlined word in the sentence? Food is an important part of any festival. (OF is the underlined word)

A. interjection

B. adverb

C. preposition

D. conjunction

C. prepostion

a word governing, and usually preceding, a noun or pronoun and expressing a relation to another word or element in the clause, as in "the man on the platform," "she arrived after dinner," "what did you do it for?"