Answer: Technician B
Explanation: A valve overlap occurs when both the exhaust valve and the inlet valve are open at the same time.
It is also seen as the number of degrees at which both the inlet and exhaust valves are open.
Valve overlap helps in boosting the efficiency of the engine by taking advantage of the expelled pressure from the exhaust.
It is expressed mathematically in degrees of shaft rotation.
So, Technician B is very correct.
