Answer:
D. Coal,oil,natural gas
Step-by-step explanation:
The main sources of energy in USA are non renewable sources of energy like coal, oil and natural gas. Oil is the main source of energy in USA while coal stands second as a source of energy. Apart from these two, natural gas is also widely used in USA as an energy source. Non renewable sources of energy are also known as conventional sources of energy. Alternate sources of energy which are also known as renewable sources of energy like wind, solar hydroelectric, geothermal energy etc. are not used commonly as main sources of energy in USA.