Nuclear energy provides nearly 20% of the electricity available in the United States. One advantage of using nuclear energy is that the uranium pellets that are used to generate the electricity are only about the size of your fingertip. It would take 150 gallons of oil to produce the same amount of energy. However, nuclear energy has disadvantages, too. What is a disadvantage of nuclear energy? A. It produces a lot of greenhouse gases and acid rain. B. It produces less energy than fossil fuels. C. It is difficult to dispose of nuclear wastes. D. It is impossible to carry on nuclear reactions safely.