Given the task definition and input, reply with output. In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D". 

[header] How to play digital music files in your car [title] Play music while driving using a cassette adapter if your car stereo accepts cassette tapes. [step] Here are the steps that you need to follow. [substeps] Insert the cassette adapter into your car's cassette player. <sep> (A) Turn the tape on, and record a blast of sound. Record this sound in your front passenger's stereo. (B) The cassette converter is a cylindrical tube with a large slot in one end. If your car stereo was designed to contain cassette tapes, the slot might be on the back of the rear speakers. (C) Dial (an auxiliary frequency if you have an aux adapter). Press " record " on the cassette adapter. (D) Plug in the wire from the cassette adapter into the headphone jack on your external device that can play digital music. Select and play the songs that you want to listen to.

D