Answer: The sound will be louder or greater amplitude.
Explanation: The energy input in the speaker relates directly to the intensity of the soundwave that the speaker creates, and the intensity of a soundwave is directly related to the "volume" of the sound. This is because the energy imput is used in the amplifiction proces, as more energy comes, bigger is the amplification of the sound.
So the correct option is the C: The sound will be louder or greater amplitude.