Given the task definition and input, reply with output. In this task, you are given a multiple-choice question and you have to pick the correct option. Answer with option indexes (i.e., "A", "B", "C", and "D").

How might you figure out what a parts are needed to let your car drive? (A) think very hard until you figure it out (B) ask the person who invented it (C) throw it in a lake and see if it floats (D) break it down and determine what it is composed of
D