Akind of sedimentary rock formed from plant material over a long period of time is
a. limestone
b. cementation
c. coal
d. compaction

From the given item, we are presented with four choices which are types of sedimentary rock. From the choices, we are to choose which among them is formed from a plant material over a long period of time. The answer to this item is letter coal. That is letter C.

Plants are the basis of a sedimentary rock, known as coal. Over the period of time, carbon is removed from the plants and combined with other organic materials. Generally, organic carbon in coal is 3%, and a major source of natural gas and oil.

Ihave no idea what the answer is