When Listening to Music, Which of the Following Methods Will

When listening to music, which of the following methods will help ensure you hear all of the frequencies represented in the piece?

A) Hold volume constant throughout the piece.
B) Turn the volume down (e.g., 20 dB) so the music is quiet.
C) Turn the volume up (e.g., 80 dB) so the music is loud.
D) Play white noise in the background to allow better discrimination.