Agree with both answers so far.
But.... variable pitch refers to any method of varying the pitch, and that includes constant speed props. Constant speed props are a sub-set of variable pitch props. The purpose of a constant speed prop, and the general way in which the settings are used, is the same as any other variable pitch prop - it's just the exact method of adjusting the pitch is different, with some of the pitch changes happening automatically.
FFF
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