Answer: C: once- living organisms
Biogenious sediments are the sediments, which can be found on the oceanic floor. These sediments consists of biological wastes secreated by marine organisms, like feces, discarded shells and decomposed or partially decomposed remains of dead animals and plants. These are finely grained sediments and 30 percent of composition belongs to the shells of microorganisms. The shells are source of calcium and silica in the sediment.