Akind of sedimentary rock formed from plant material over a long period of time is

a.

limestone

b.

cementation

c.

coal

d.

compaction

A kind of sedimentary rock formed from plant material over a long period of time is : Coal
In order for coal to be created, it needed a lot of decomposition from dead organisms, such as dead plants and animals. our nature need million of years before it could naturally transform the dead substances into a flammable substance such as coal and oil

Ithink the answer is d.