The correct answer is D. All of the above.
Pneumatic manipulators are powered by compressed air. Electric manipulators are powered by electricity. Hydraulic manipulators are powered by hydraulic fluid.
Pneumatic manipulators are typically used in applications where there is a need for high power and speed. They are also often used in applications where there is a need for a clean environment, as they do not produce any emissions.
Electric manipulators are typically used in applications where there is a need for precision and control. They are also often used in applications where there is a need for a quiet environment, as they do not produce any noise.
Hydraulic manipulators are typically used in applications where there is a need for high force and torque. They are also often used in applications where there is a need for a rugged environment, as they are not easily damaged by water or other liquids.
In conclusion, the power source that drives the manipulator can be pneumatic, electric, or hydraulic. The choice of power source will depend on the specific application.