Concept:Organic farming improves soil health by using natural materials such as compost and animal manure.
Explanation:Organic farming avoids the use of artificial chemicals and synthetic fertilizers.
Instead, farmers use compost, green manure, and animal waste to nourish the soil.
These organic materials decompose and release essential nutrients into the soil.
This process adds humus, improves soil structure, and supports helpful soil organisms.
As a result, the soil becomes richer and more fertile over time.
Thus, a clear advantage of practicing organic farming is that it increases soil fertility.
The other options are not guaranteed direct effects of every organic farming practice.
Answer:A. increases soil fertility.