Concept:Some soil organisms are beneficial to crops and are called farmer’s friends.
Explanation:Earthworms help the farmer by improving the soil.
They burrow through the soil, creating spaces for air and water.
Their castings add nutrients to the soil.
Therefore, earthworms improve soil structure, aeration, and fertility.
Aphids, grasshoppers, and termites are pests because they damage crops or farm structures.
Answer:A. earthworm