Each time the distance from the speaker is doubled， volume decreases by（）.

A.As voltage increases， resistance decreases
B.As amperage decreases， resistance decreases
C.As resistance decreases， amperage increases
D.As resistance increases， voltage increases

A.distance
B.power
C.size
D.efficiency

A.Contains four pair of wires of various gauge
B.Contains two wires in a red fireproof jacket
C.Contains four twisted pairs of wires
D.Contains eight wires within a thick jacket with a rip cord