The correct answer is D. (B) and (C) above.
Hydraulic and pneumatic actuators are both types of fluid power actuators. They generate a good deal of power, but they can be messy because they use fluids. Hydraulic actuators use oil, while pneumatic actuators use air.
Electric actuators are a type of non-fluid power actuator. They are not as messy as hydraulic or pneumatic actuators, but they do not generate as much power.
Here is a more detailed explanation of each option:
- Option A: Electric actuators are powered by electricity. They are a type of non-fluid power actuator. They are not as messy as hydraulic or pneumatic actuators, but they do not generate as much power.
- Option B: Hydraulic actuators are powered by hydraulic fluid. They are a type of fluid power actuator. They generate a good deal of power, but they can be messy because they use fluids.
- Option C: Pneumatic actuators are powered by compressed air. They are a type of fluid power actuator. They generate a good deal of power, but they can be messy because they use fluids.
- Option D: (B) and (C) above. This is the correct answer. Hydraulic and pneumatic actuators are both types of fluid power actuators. They generate a good deal of power, but they can be messy because they use fluids.
- Option E: None of the above. This is the incorrect answer. Hydraulic and pneumatic actuators are both types of fluid power actuators. They generate a good deal of power, but they can be messy because they use fluids.