Answer:
b. Repeatedly reverses the flow of current through the armature.
Step-by-step explanation:
- The electric motor is a device that converts the electrical energy into mechanical energy. 
- The commutator is a device that repeatedly reverses the flow of current through the armature. 
- It is a split ring that acts as the commutator. 
- It connects the external circuit through a carbon brush and the armature of the motor. 
- Another important component of an electric motor is an electromagnet or permanent magnet.