Clearance volume scavenging in a turbocharged, four-stroke/cycle diesel engine is accomplished __________.

Correct Answer: Option A — during the valve overlap period

Scavenging of the clearance volume in a four-stroke engine occurs during valve overlap when both intake and exhaust valves are momentarily open. High-pressure charge air sweeps residual exhaust gases from the combustion chamber, ensuring a clean, oxygen-dense charge for the upcoming power stroke.