When stripping a tank, what is caused by excessive air in the suction line?

Correct Answer: Option C — loss of suction

Centrifugal pumps rely on a solid column of liquid to maintain prime. Excessive air in the suction line breaks this column, causing the pump to become 'air-bound.' This results in a loss of suction, preventing the pump from moving fluid and potentially damaging the pump internals due to cavitation.