The automatic level control (ALC) in an SSB transmitter:

Automatic Level Control (ALC) is a crucial protective circuit found in SSB transmitters. Its primary function is to monitor the RF output level and automatically reduce the gain of earlier amplifier stages if the input audio peaks become excessively loud. This limits the input so the transmitter is not overdriven. Overdriving an SSB transmitter causes the amplifier to operate outside its linear range. When this happens, the signal distorts heavily and generates spurious emissions called 'splatter,' which increases the occupied bandwidth and causes harmful interference to adjacent stations. The other options are incorrect because ALC does not reduce system noise or audio feedback. Furthermore, ALC actually prevents an increase in occupied bandwidth by stopping the distortion that causes splatter.