The correct answer is A. Sulphur.
Vulcanization is a chemical process that converts natural rubber into a more durable material. It is carried out by adding sulphur to rubber and heating it. The sulphur reacts with the rubber molecules to form cross-links, which make the rubber stronger and more resistant to wear and tear.
Carbon, ozone, and phosphorus are not used in the vulcanization process. Carbon is a non-metal that is found in coal, oil, and natural gas. Ozone is a gas that is formed when oxygen molecules are split by ultraviolet radiation. Phosphorus is a non-metal that is found in rocks and minerals.
Vulcanization is a very important process that has many applications. It is used to make tires, shoes, hoses, and other products that need to be strong and durable.