When cleaning a tank by the Butterworth process, you should begin to pump out the slops __________.

Correct Answer: Option A — when the process is started

Continuous stripping during tank cleaning operations, such as Butterworth washing, is essential to prevent slop water and oily residue from accumulating on the tank bottom. Pumping out slops from the moment washing begins ensures optimal wash efficiency, prevents slop build-up, and minimizes the risk of static electricity accumulation within liquid puddles.