Answer:
The correct option is A. Chemical energy to thermal energy.
Step-by-step explanation:
Although there are many renewable sources of energy, humans still majorly rely on non- renewable sources of energy.
The simplest way to describe fossil fuels are as fuels derived from long ago dead organisms. Fossil fuels have an active composition of hydrocarbons in them. By burning these fossil fuels, the chemical energy stored in them is converted into thermal and electrical energy for various purposes.
Coal, oil and natural gas are the major types of fossil fuels.