Why is scavenging of exhaust gases important in diesel engines?

Scavenging of exhaust gases in diesel engines is crucial because it facilitates the complete combustion of fuel. This process involves effectively removing the spent exhaust gases from the combustion chamber after the power stroke. By ensuring that the chamber is free of these residual gases, fresh air can enter in sufficient quantities, leading to a more efficient combustion process.

When combustion is complete, it means that more of the fuel is converted to energy, resulting in improved performance and power output of the engine. Adequate scavenging helps in maintaining optimal engine efficiency and minimizes the risks of unburned fuel contaminating the engine oil or the generation of harmful emissions. This is essential not only for the engine's performance but also for compliance with environmental regulations.

The other options, while relevant in certain contexts, do not specifically capture the primary significance of scavenging in promoting complete fuel combustion.