Correct option is D
A synchronous motor is not self-starting because it requires an external means to reach its synchronous speed before it can operate. This is due to the fact that the rotor does not develop any starting torque on its own in an AC supply.
To start a synchronous motor, auxiliary methods such as:
· Damper windings (in salient pole machines)
· Using a separate DC motor to bring it up to speed
· Starting with an external prime mover are employed.
