The correct option is C This organic matter is usually formed from the remains of marine organisms.
The formation of coal starts from the dead organisms from land getting buried under the earth. This organic matter, in its decomposed form, remains buried for millions of years. In this time, layers of organic matter are formed, wherein one layer would be on top of the other. These layers undergo certain changes due to heat and pressure inside the Earth. They gradually transform into a black coloured substance, called coal. It is for this reason that coal is also known as buried sunshine.