A surface receiving sound is moved from its original position to a position three times farther away from the source of the sound. The intensity of the received sound thus becomes
Athree times as low.
Bnine times as high.
Cthree times as high.
Dnine times as low.
Athree times as low.
Bnine times as high.
Cthree times as high.
Dnine times as low.