Which of the following is a type of starting system for an engine?

The correct answer indicates that all the listed systems—hydraulic, electric, and pneumatic—are potential types of starting systems for an engine.

An electric starting system is the most common, utilizing a battery to provide the necessary power to crank the engine. This type of system engages the starter motor, which turns the engine over, allowing it to begin its combustion cycle.

A hydraulic starting system employs hydraulic pressure to start the engine, often used in larger machinery or specific applications where electric systems may not be feasible. This method typically involves a hydraulic pump and motor that create the force needed to crank the engine.

A pneumatic starting system uses compressed air to turn over the engine. This system is particularly useful in very large engines, such as those found in ships, because it offers the ability to start under high loads without the risk of electrical failure in extreme environments.

Since all three systems can effectively serve the purpose of starting an engine in various applications, the answer encompasses the variety of methodologies available for engine starting.