'Humus' is made up of

Answer: Option C

Humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is rich in nutrients and retains moisture in the soil.
Humus is made up of both Humic materials and non-humic materials.
Humic materials include major components of the natural organic matter in the soil and water like lake sediments, peats, brown coals and shales.
Non-humic substances are compounds related to biochemistry such as sugars, amino acids, fats, etc.