How can the chance of contaminating hydraulic fluid be decreased when working on hydraulic systems?

Correct Answer: Option C — Clean the fittings before they are disconnected.

Contamination is the leading cause of hydraulic system failure. Cleaning the exterior of fittings and surrounding areas before disconnection prevents debris from entering the lines. This practice is vital for maintaining the integrity of precision components like pumps and valves, as mandated by good marine engineering maintenance procedures.