Which of the following represents the motivating power fluid used in conjunction with the ejector pumps on plate type evaporators?

Correct Answer: Option C — The motive power is the feed water supply.

Ejector pumps in plate-type evaporators utilize the Venturi effect to create a vacuum. The feed water supply acts as the motive fluid, passing through a nozzle to create a low-pressure zone that draws air and non-condensable gases out of the evaporator chamber, maintaining the necessary vacuum.