What is essential for the proper operation of a pneumatic tool?

For the proper operation of a pneumatic tool, compressed air is essential. Pneumatic tools are specifically designed to use air pressure to perform tasks such as drilling, fastening, and impact wrenches. They rely on the energy provided by compressed air to activate their mechanisms, providing a powerful and efficient means of performing work.

In contrast to the other options, which involve different forms of energy or power sources — electricity typically powers electric tools, battery power is used in cordless tools, and hydraulic fluid is required for hydraulic tools — pneumatic tools exclusively function through the use of air pressure. This characteristic makes compressed air not just an important but the fundamental requirement for the operation of pneumatic tools.