The picture shows a basic diagram of an electric motor. At top left a piece of magnet labeled N and at top right a piece labeled S. Between these a square coil of wire X sits attached to a metal rod, which runs between the 2 pieces of magnet. 2 semicircular pieces Z of metal surround the rod at its opposite end from the pieces of magnet. Wires connect to each semicircular piece at terminals Y to one pole of a battery. Blue arrows superimposed on the end of the coil away from the magnets point toward S and away from N. Which labels best complete the diagram? X: Brush Y: Armature Z: Commutator X: Commutator Y: Brush Z: Armature X: Armature Y: Commutator Z: Brush X: Armature Y: Brush Z: Commutator