When inspecting a distributor cap with a carbon brush, you should?

when inspecting a distributor cap with a carbon brush, you should?

A.ensure the carbon ball is free
B.remove the rotor button
C.check the brush for freedom of movement
D.use a screw driver to remove the center tower
some one tell whats the answer cause I need help on my homework

The carbon brush conducts the voltage passing the contacts to discharge it through the spark plugs and it has to be free to move properly.