Where does the organic material in soil originate?
a.
physical weathering
b.
chemical weathering
c.
decomposing plant and animal matter
d.
the atmosphere

Option C

Explanation: The organic matter in the soil comes by the decomposition of the plant and animals in the soil.

When the plants and animals die the decomposers like fungi and bacteria decompose the organic matter into the more simple organic matter such as carbon.

This process recycles the nutrient back into the soil that adds fertility to soil.

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation: