Answer:
a. coal
Explanation:
The most abundant nonrenewable resources in the world is the coal. Actually, the coal is so abundant when compared to the other nonrenewable resources that it simply dwarfs the others. For example, the United States have much more coal reserves than what all of the world combined has in oil reserves, and when on that are put the likes of China, India, Australia, Mongolia etc., the coal surpasses the other nonrenewable resources by far.
The coal is fossil fuel. It has been created over millions of years, with its basis being the wood, mostly from the Permian period, and being exposed to higher temperature and pressure, it has gradually turned into a sedimentary type of rock that produces enormous amounts of energy.
While the energy production of the coal is immense, and it is good for the industry, it is very bad for the environment, as it causes lot of pollution. This is why over the last century the more developed countries have started to gradually move away from it and replace it with other resources.
