The correct answer is A. Repulsion motor.
A repulsion motor has the highest starting torque of all the motors listed. It is a type of single-phase induction motor that uses a stator winding and a rotor winding that are not connected to each other. The stator winding is energized with an alternating current, which creates a rotating magnetic field. The rotor winding is not energized, but it is attracted to the rotating magnetic field of the stator. This attraction causes the rotor to turn.
The repulsion motor has a high starting torque because the rotor is attracted to the rotating magnetic field of the stator. This high starting torque makes the repulsion motor ideal for applications where a large amount of torque is required at startup, such as in conveyors and elevators.
The other motors listed do not have as high of a starting torque as the repulsion motor. The shaded pole motor has a lower starting torque because the rotor winding is not energized. The capacitor-start motor has a lower starting torque because the capacitor is used to create a phase shift between the stator windings, which reduces the amount of torque that is produced. The split-phase motor has a lower starting torque because the two stator windings are not energized at the same time, which also reduces the amount of torque that is produced.
In conclusion, the repulsion motor has the highest starting torque of all the motors listed. This high starting torque makes the repulsion motor ideal for applications where a large amount of torque is required at startup.