Answer : Option D

Explanation :

The term scavenging is generally associated with High efficiency engines. In Automobiles, Scavenging is a process of pushing exhaust gas out of the cylinder and drawing in fresh draught of air or air fuel mixture for the next cycle. The process is essential in having a smooth running of I.C. Engine. If scavenging is incomplete the following stroke will begin with a mix of exhaust fumes rather than clean air. This may be insufficient for poor combustion which leading to poor running condition on an engine. Scavenging is equally important for both 2 Stroke and 4 Stroke Engine. However, it is more difficult to achieve in 2 Stroke engine.