In the process of vulcanization:(a) natural rubber is heated with Sulphur(b) natural rubber is heated with carbon(c) natural rubber is heated with phosphorus(d) natural rubber is heated with sodium

In the process of vulcanization, natural rubber is heated with sulfur to improve its properties. This process enhances the elasticity, strength, and durability of rubber, making it more resistant to heat, cold, and wear. Vulcanization involves forming cross-links between the polymer chains of rubber by introducing sulfur atoms. These cross-links prevent the chains from sliding past one another, thus improving the mechanical properties of rubber.

Explanation:
Natural rubber consists of long chains of the polymer polyisoprene. Without vulcanization, rubber is sticky, brittle at cold temperatures, and loses its shape when heated.
Sulfur atoms form cross-links (sulfur bridges) between the rubber polymer chains, providing flexibility at a wide range of temperatures and improving its resistance to chemicals and abrasion.
The correct option is: (a) natural rubber is heated with sulfur.