Question ID:PT61 S2 Q16 Passage:Engineer:  Thermophotovoltaic generators are devices that convert heat into electricity. The process of manufacturing steel produces huge amounts of heat that currently go to waste. So if steel-manufacturing plants could feed the heat they produce into thermophotovoltaic generators, they would greatly reduce their electric bills, thereby saving money. Stem:Which one of the following is an assumption on which the engineer's argument depends? Correct Answer Choice:CChoice A:There is no other means of utilizing the heat produced by the steel-manufacturing process that would be more cost effective than installing thermophotovoltaic generators. Choice B:Using current technology, it would be possible for steel-manufacturing plants to feed the heat they produce into thermophotovoltaic generators in such a way that those generators could convert at least some of that heat into electricity. Choice C:The amount steel-manufacturing plants would save on their electric bills by feeding heat into thermophotovoltaic generators would be sufficient to cover the cost of purchasing and installing those generators. Choice D:At least some steel-manufacturing plants rely on electricity as their primary source of energy in the steel-manufacturing process. Choice E:There are at least some steel-manufacturing plants that could greatly reduce their electricity bills only if they used some method of converting wasted heat or other energy from the steel-manufacturing process into electricity.