Two technicians are discussing disc brake rotor service. Technician A says that the inner races (bearing cups) should be removed from the rotor before it is mounted on the lathe. Technician B says that a non-directional finish on the rotor surfaces can be obtained by using sandpaper. Which technician is correct?
A) Technician A only
B) Technician B only
C) Both technicians
D) Neither technician