Introduction:
In electrical engineering, starting torque refers to the torque or rotational force generated by a motor at the moment it is switched on. It is an important parameter to consider when selecting a motor for applications that require high torque during startup. Among the given options, the repulsion motor has the largest starting torque.

Explanation:
Let's discuss each of the given options and understand why the repulsion motor has the largest starting torque.

1. Shaded-pole motor:
A shaded-pole motor is a type of single-phase induction motor. It consists of a stator with salient poles and a squirrel-cage rotor. The starting torque of a shaded-pole motor is relatively low compared to other types of motors. It is typically used in low-power applications where high starting torque is not required.

2. Capacitor-start motor:
A capacitor-start motor is also a single-phase induction motor. It uses a capacitor to create a phase difference between the main and auxiliary winding, which helps in starting the motor. The starting torque of a capacitor-start motor is higher than that of a shaded-pole motor but lower than a split-phase motor or a repulsion motor.

3. Split-phase motor:
A split-phase motor is another type of single-phase induction motor. It uses a special starting winding and a centrifugal switch to create a phase difference during startup. The starting torque of a split-phase motor is higher than that of a shaded-pole motor and a capacitor-start motor but lower than a repulsion motor.

4. Repulsion motor:
A repulsion motor is a type of single-phase synchronous motor. It uses brushes and commutator segments to create a rotating magnetic field. The starting torque of a repulsion motor is the highest among the given options. The brushes and commutator allow the motor to achieve high torque during startup. This makes it suitable for applications that require high starting torque, such as in hoists, cranes, and elevators.

Conclusion:
Among the given options, the repulsion motor has the largest starting torque. It is capable of generating high torque during startup due to its unique design with brushes and commutator segments.