Explanation: A Class C amplifier is biased such that the active device (transistor or vacuum tube) is driven into conduction for significantly less than one-half (180 degrees) of the input signal cycle. It operates with a bias voltage that places it well into cutoff. Current only flows when the input signal's peak drives the device out of cutoff for a brief period. This results in a conduction angle typically ranging from 90 to 150 degrees, which is always less than 180 degrees. This mode of operation is highly efficient and commonly used for RF power amplification, where a resonant tank circuit connected to the output reconstructs the full sinusoidal waveform from these short current pulses. * **A) Less than 180 degrees:** This is correct, as explained above. * **B) Exactly 180 degrees:** This describes Class B amplifier operation. * **C) 360 degrees:** This describes Class A amplifier operation. * **D) More than 180 but less than 360 degrees:** This describes Class AB amplifier operation.