In Buna-S, the symbol S stands for :

Options

A. sulphur
B. soft
C. Styrene
D. sodium

Explanation

To answer the question "In Buna-S, the symbol S stands for:", we need to analyze the components that make up Buna-S and what the symbol 'S' represents in this context.

### Step-by-Step Solution:

1. **Understanding Buna-S**:
- Buna-S is a type of synthetic rubber. It is a copolymer made from two different monomers.

2. **Identifying the Monomers**:
- The two monomers used to create Buna-S are:
- 1,3-butadiene (which is represented as CH2=CH-CH=CH2)
- Styrene (which is represented as CH2=CH-C6H5)

3. **Copolymerization Process**:
- Copolymerization is the process where two different types of monomers combine to form a polymer. In the case of Buna-S, 1,3-butadiene and styrene undergo copolymerization.

4. **Determining the Meaning of 'S'**:
- In the name Buna-S, the 'S' specifically refers to the styrene monomer. Thus, the full name of Buna-S can also be referred to as "butadiene-styrene rubber."

5. **Conclusion**:
- Therefore, the symbol 'S' in Buna-S stands for **styrene**.

### Final Answer:
In Buna-S, the symbol S stands for **styrene**.