What is the function of the switch which selects either SSB or CW-FM on some VHF power amplifiers?

Answer: B. Set the amplifier for proper operation in the selected mode

Some VHF amplifiers have a switch for SSB or CW-FM so the amplifier is set up to work properly in that mode. SSB needs a linear amplifier, while CW and FM can use a more efficient, non-linear setting. The switch does not change the mode the radio transmits.

Tip: The switch sets up the amp, not the radio's mode.