Millions of years ago in many different regions of the world, large-scale burials of organic matter were followed by the formation of underground traps. Which of the following provides evidence of these past geologic processes?

A.
Areas where these geologic processes occurred now have major petroleum reserves.
B.
Areas where these geologic processes occurred now have very fertile soil.
C.
Areas where these geologic processes occurred now have major groundwater reserves.
D.
Areas where these geologic processes occurred now have very few natural resources.