Which of the Following Is True About Audio Messages

Which of the following is true about audio messages?

A) Jingles work best when they are introduced in a video ad first, before translating it to an audio-only format.
B) The voiceover speaker or actors should maintain an even tone to ensure comprehension.
C) Brands employ unique sound effects to allow the visual to take hold in the receiver's mind.
D) Music is not as much of a key component in audio messages, as it can muddle the meaning of the message.