sat-dog

Choice B is the best answer because it most accurately describes the main purpose of the text, which is to explain the basics of how a specific energy technology works. The text introduces Raccoon Mountain as a pumped-storage hydropower facility built in the 1970s and then explains how it operates: during periods of low demand, excess power pumps water up to a lake at the mountain’s summit, and when demand for energy peaks, the water flows back down, spinning turbines along the way to generate electricity. The text provides some additional details, like the name of the water source, but the overall focus is on explaining the basics of how pumped-storage hydropower works. Choice A is incorrect because the text focuses on one method of energy generation—pumped-water hydropower—and briefly mentions another type of energy generation (nuclear plants) only to identify it as a source of power for the pumping process. The text never makes any comparison between the two methods. Choice C is incorrect because the text simply gives a factual description of how Raccoon Mountain, a pumped-storage hydropower facility, operates; it never suggests that more energy storage facilities should be built, whether by regional utilities or by any other entity. Choice D is incorrect because the text doesn’t present pumped-storage hydropower as a new technology; it indicates that Raccoon Mountain was built in the 1970s, meaning that, rather than being new, this facility is approximately 50 years old.