Most energy sources of the earth were originally supplied from wind energy nuclear energy geothermal energy solar energy

I believe it's solar energy

Hope this helps :)

Correct D). Solar Energy

Most of the energy on the earth is obtained from the light and heat coming from the sun. These light and heat are stored in a fuel such as oil and coal, which are formed by the fossil remains of plants and animals over millions of years.

The energy of the sun is converted to carbon compound by the plants as they grow. When plants die they are converted to dark earth like substance called as a peat. These peat are buried in the earth surface and after millions of years, they form coal.

layer 3 is younger than layer 6.