What are the three main lubricants used in moving parts of a machine?

Correct option is C

The correct answer is (c) Oil, grease, graphite.
The three main lubricants commonly used in the moving parts of machines are:
1. Oil: Often used in engines and machinery to reduce friction between metal parts and ensure smooth motion.
2. Grease: A thicker lubricant that remains in place longer, commonly used in bearings, joints, and heavy machinery.
3. Graphite: A solid lubricant used in high-temperature environments where oils and greases might break down. It is also used in locks and other delicate mechanisms.
These lubricants reduce friction, wear, and heat in moving machine parts, ensuring better performance and longevity of the components.