I thought the last one was C, becuase it included the destructive interference resulting in cancellation of sound and therefore apparent distortion. The bit about "different freqs reflect differently" is just saying that theres a lot of freqs hitting the wall and bouncing back to superimpose...
but i could be wrong
C - Without the curtains,
different frequencies will reflect differently from the walls, causing distortion due to interference effects.
D - Without the curtains, there would be multiple paths from the speaker to each member of the audience, thus causing distortion and sound loss due to interference effects in some parts of the theatre.
that's the only thing I didn't like about C.
that and, D is more "complete" in saying that there will be distortion as well as sound loss, but only in
some partsanyhow, I could be entirely wrong about different frequencies all reflecting the same...
Fidgey: it does say "smallest wavelength". sorry buddy.