Why will a turbocharged diesel engine produce black smoke if excessive additional load is applied too quickly?

Correct Answer: Option B — The inertia of the turbocharger rotor causes a time lag which delays the turbocharger speed increase.

Applying sudden heavy loads causes immediate fuel injection increase, but turbocharger rotor inertia creates a rotational time lag. The temporary air-fuel deficit produces incomplete combustion, carbon particulates, and characteristic black smoke until turbine speed catches up.