Assertion`:` In vulcanisation of rubber , sulphur cross links are introduced.
Reason`:` Vulcanisation is a free radical intiated chain reaction.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion .
B. If both assertion and reason are true but reason is not the correct explanation of assertion .
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understanding the Assertion
The assertion states that "In vulcanisation of rubber, sulphur cross links are introduced."

- **Explanation**: Vulcanization is a chemical process that involves heating natural rubber with sulfur. The sulfur atoms form cross-links between the long chains of rubber molecules. This process enhances the strength, elasticity, and thermal stability of rubber, making it more durable and suitable for various applications.

### Step 2: Understanding the Reason
The reason states that "Vulcanisation is a free radical initiated chain reaction."

- **Explanation**: The vulcanization process can indeed involve free radicals. During the heating process, sulfur can initiate a free radical mechanism that leads to the formation of cross-links between rubber chains. This means that the assertion is correct, and the reason also correctly describes a mechanism involved in vulcanization.

### Step 3: Conclusion
Both the assertion and the reason are true statements. The reason correctly explains the assertion. Therefore, we can conclude that both the assertion and the reason are correct and that the reason supports the assertion.

### Final Answer
- **Assertion**: True
- **Reason**: True
- **Conclusion**: Both the assertion and the reason are correct, with the reason providing an explanation for the assertion.

---