In the event of a crankcase rich oil mist to air mixture explosion, where the doors are blown off the engine, which of the following may occur after the initial explosion?

Correct Answer: Option A — A secondary explosion as air is drawn back into the crankcase.

When crankcase doors blow off during an oil mist explosion, cool outside air is rapidly drawn into the hot crankcase. This introduces oxygen to unburned combustible vapors, frequently triggering a destructive secondary explosion.