Forgot who I was responding to, this is a test isn't it?
Any mass, connected to and rotating around an axis will have a CF. The only way to zero CF is to move the axis parallel to the path the mass would travel if not connected. --OR-- (for the sake of brevity)
The left arm is always swinging.
Bumpy
Left arm is moving, but not from pivot power, only from the right triceps. Check out the yellow book - Hitting accumulators are 1,2,3. No #4.