Respuesta :
Ans: B) United States and Russia
Energy sources can be broadly classified into two categories: Renewable and non-renewable sources.
Renewable sources are those that can be naturally replenished like, solar energy, wind, hydrothermal etc
In contrast, non-renewable sources of energy are a finite resources and cannot be replenished. Fossil fuels like coal, oil, gas are all non-renewable sources. Coal is the most widely used source of energy with the United States and Russia being the two countries that have nearly 50% of the global coal reserves.