In an AM signal the received signal power is 10 10 W with a maximum modulation signal of 5 kHz. The noise spectral density at the receiver input is 10 18 W/Hz. If the noise power is restricted to the message signal bandwidth only, the signal-to-noise ratio at the input to the receiver is

• A. 43 dB
• B. 66 dB
• C. 56 dB
• D. 33 dB