Correct Response: A. The system described in choice A satisfies the requirements of the question. The system is open since the water is not recirculated, the system is geothermal since the hot springs are naturally heated by the earth’s internal temperature, and the system involves a heat pump in the form of a refrigerant that is compressed to a liquid and allowed to expand to gas in an evaporator coil. Choice B is not primarily powered by geothermal energy and it does not involve a heat pump. Choice C is not an open system and it does not involve a heat pump. Choice D does not involve a heat pump.