If valve "D" is opened during the normal operation of the distiller shown in the illustration, which of the events listed will occur? Illustration MO-0111

Correct Answer: Option C — The amount of vapor being formed in the evaporator will decrease.

Opening valve D introduces a bypass or alters the flow path, reducing the heat transfer efficiency or the vacuum level within the evaporator. By disrupting the thermal balance or pressure differential required for efficient boiling, the rate of evaporation decreases, directly resulting in less vapor production for the condenser.