Concept:Clay soil has fine particles that make it dense, poorly drained, and hard to work.
Adding organic matter improves its structure and porosity.
Explanation:Clay soil holds too much water and drains slowly because its particles pack tightly together.
Organic material, such as compost or manure, helps bind the tiny clay particles into larger crumbs.
This creates bigger pore spaces, which improves drainage, aeration, and root penetration.
It also increases the soil’s ability to hold and release plant nutrients.
Acid-forming fertilizers, bush burning, and sodium chloride would damage clay soil further or make it saline.
Therefore, the best practice is adding organic material.
Answer:B. addition of organic material.