The horizon of the soil profile that encourages the greatest level of microbial activity is
- D -horizon
-
A-horizon
- C-horizon
- B-horizon
The correct answer is: B
Explanation
The A-horizon, also known as the topsoil, is the layer of soil that encourages the greatest level of microbial activity. This is because it contains the highest amount of organic matter and nutrients, which are essential for microbial growth and activity.