C.Leticia offered to bring the party supplies.
An infinitive is a verb phrase that starts with "to". In this sentence "to bring" is the infinitive. It begins with the word "to" and is followed by the verb "bring". Options B and D do not contain the word "to" so they can be eliminated immediately. Option A contains the phrase "to the movies" which begins with the word "to". However, this is a prepositional phrase because it ends with a noun, "movies", and not a verb.