Question

The earth’s most important nonrenewable energy source is _____.

Answer 1

The earth’s most important nonrenewable energy source is "coal".

Non-renewable energy source refers to a source of energy that will in the end run out. Most sources of non-renewable energy source are fossil fuels, for example, coal, gas and oil.  

These natural resources are a noteworthy wellspring of intensity for an immense measure of businesses – be that as it may, there are various drawbacks to non-sustainable power source, including their negative ecological effect and the reality they are in constrained supply.  

Coal originates from the remaining parts of plants that died a huge number of years prior. It has the most abnormal amount of carbon of every single non-renewable energy source.

Answer 2

C is wrong. I think it's A