The correct answer is: C. Compound motor
A compound motor is a type of DC motor that has both series and shunt windings. The series winding is connected in series with the armature, while the shunt winding is connected in parallel with the armature. This gives the compound motor the best of both worlds: the high starting torque of a series motor and the constant speed of a shunt motor.
A compound motor is the best choice for a load that has a certain minimum value for most of the time and some peak value for short duration. The series winding will provide the high starting torque needed to get the load moving, while the shunt winding will provide the constant speed needed to keep the load running smoothly.
A series motor is a type of DC motor that has the field winding connected in series with the armature. This means that the current through the field winding is the same as the current through the armature. This gives the series motor a high starting torque, but it also means that the speed of the motor is very sensitive to the load. A series motor is not a good choice for a load that has a certain minimum value for most of the time and some peak value for short duration, because the motor will not be able to maintain a constant speed under these conditions.
A shunt motor is a type of DC motor that has the field winding connected in parallel with the armature. This means that the current through the field winding is independent of the current through the armature. This gives the shunt motor a constant speed, but it also means that the starting torque is relatively low. A shunt motor is a good choice for a load that has a constant speed requirement, but it is not a good choice for a load that has a certain minimum value for most of the time and some peak value for short duration, because the motor will not be able to provide the high starting torque needed to get the load moving.