Answer: A) Serena.
Explanation: the subject of a sentence is the person, animal, or thing that performs the action of the verb. It is one of the main parts of a sentence (there is no sentence without a subject or a verb). In the given sentence the verb is "drove" and the person that performs the action of the verb (the subject) is "Serena." The word "car" is the direct object of the sentence and the words "shiny" and "new" are complements.