E4D12 - Amateur Extra Class

E4D12 : What is the link margin in a system with a transmit power level of 10 W (+40 dBm), a system antenna gain of 10 dBi, a cable loss of 3 dB, a path loss of 136 dB, a receiver minimum discernable signal of -103 dBm, and a required signal-to-noise ratio of 6 dB?
A -8dB
B -14dB
C +8dB
D +14dB
Correct Answer: +8dB