The correct answer is C. Sulphur.
Vulcanization is a chemical process that converts natural rubber into a more durable material. It is achieved by heating natural rubber with sulfur. The sulfur reacts with the rubber molecules to form cross-links, which make the rubber stronger and more resistant to wear and tear.
Carbon, silicon, and phosphorus are not used in vulcanization. Carbon is a non-metal that is found in coal, diamonds, and graphite. Silicon is a metalloid that is found in sand, quartz, and silicone. Phosphorus is a non-metal that is found in bones, teeth, and fertilizer.
Vulcanization is a very important process that has many applications. It is used to make tires, shoes, hoses, and many other products.