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.
Cnine times as low.
Dthree times as high.
Athree times as low.
Bnine times as high.
Cnine times as low.
Dthree times as high.