The uppermost horizon, horizon o, in this profile is composed mostly of while the lower horizon, horizon c, is composed mostly of a) silt; gravel. b) gravel; rocks. c) organic matter; rocks. d) top soil; organic matter.

Answer;

C) organic matter; rocks.

The uppermost horizon, horizon O, in this profile is composed mostly of organic matter, while the lower horizon, horizon C, is composed mostly of rocks.

Explanation;

-Soil contains the following major horizons, that is A B and C. Some soils may have horizon O, which may be thin or thick or even lack in some soils. This O horizon is found at the surface of many soils and normally contains organic materials at various decomposition stages. these are materials such as plants, leaves and bugs.

-C horizon is the layer that is below the B horizon. It contains larger weathered fragments or broken up-bedrock.

the sphincter muscles at the end of the digestive tract is the anus.