How do earthworms enrich plant growth? they secrete oil from their skin that fertilizes the soil? they eat dead leaves that are harmful to plants. they tunnel through the soil, which allows air to enter. they eat insects that destroy plant roots.

They tunnel through the soil, which allows air to enter.

Explanation:

Earthworms are considered to be agriculturally friendly living organisms that hold immense importance in improving the growth and productivity of plants.

They live in the soil and feed on the debris of plants such as manure, grasses, roots and dead leaves. They extensively channel and tunnel through soils while moving that causes loosening of the soil resulting in more aeration of the soil. The more the soil aeration is, the better soil drainage is.

Studies have shown that soil containing earthworms have ten times better drainage than soils that donot have earthworms. Therefore, C is the best option.

Hope it help!

protistas excret ethanol used in the manufacture of vinegar