D = vt = 340X4 = 1360 m

IL = 10 log(I/10-12)

105 = 10 log(I/10-12)

log(I/10-12) = 10.5

I = 3.16X1010X10-12 = 3.16X10-2 W/m2

P = 4p(1360)2X 3.16X10-2 = 7.35X105 W

Answer is D

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