Pneumatics systems require __________.

• A. fluids such as oil or water to operate
• B. carbon Dioxide
• C. nitric Oxide
• D. a compressor

Answer: (D)

Pneumatic systems operate using compressed air to power actuators. To supply that air at the right pressure, you need a compressor. Fluids like oil or water are used in hydraulic systems, not pneumatics, and while other gases can be present in some setups, standard pneumatic systems rely on compressed air generated by a compressor.