Which of the following statements represents an advantage of a triple-effect submerged tube evaporator compared to a single- effect submerged tube evaporator?

In USCG Marine Engineering General Subjects, for engine room systems involving 'Which of the following statements represents an advantage of a triple-effect submerged tube evaporator compared to a single- effect submerged tube evaporator', the standard operating requirement is: 'Lower consumption of steam per pound of distillate produced'.