Coal and other fossil fuels are considered to be "nonrenewable" sources of energy. How does the use of nonrenewable fuels affect the total energy of the universe? A. Nonrenewable energy sources reduce the total energy by using up thermal or kinetic energy. B. Nonrenewable sources of energy add to the total energy of the universe as they are used. C. The burning of fossil fuels permanently reduces the total energy of the universe by using up chemical energy. D. Although the total energy remains constant, nonrenewable fuels convert chemical energy into forms that are difficult or impossible to use again.