Which modulation technique varies the frequency of the carrier signal based on the input signal?

A) Amplitude Modulation (AM)

B) Frequency Modulation (FM)

C) Phase Modulation (PM)

D) Pulse Code Modulation (PCM)

Answer: B) Frequency Modulation (FM)

Explanation: Frequency Modulation (FM) encodes information by varying the frequency of the carrier wave according to the input signal. FM is widely used in radio broadcasting and communications..