Which of the following does not represent polymerisation of alkenes and alkynes?

Options

A. `nCH-=Chto(--CH=CH-CH=CH--)_(n)`
B.
C. `nCH_(3)-CH=CH_(2)to underset(CH_(3))underset(|)((--CH-CH_(2)--))_(n)`
D. `nCH_(2)=CH_(2) to (--CH_(2)-CH=CH-CH_(2)--)_(n)`

Explanation

To determine which of the following options does not represent the polymerization of alkenes and alkynes, we need to analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Polymerization**:
- Polymerization is the process where small molecules called monomers join together to form a larger molecule known as a polymer. This typically occurs through the breaking of double or triple bonds in alkenes or alkynes.

2. **Analyzing Each Option**:
- **Option A**: This option involves the polymerization of ethyne (acetylene, CH≡CH). When ethyne undergoes polymerization, the triple bond breaks, allowing the carbon atoms to form single bonds with adjacent ethyne molecules, resulting in polyethyne (or polyethylene). This is a valid polymerization process.

- **Option B**: This option mentions a trimer of ethyne, which means three ethyne molecules are joining together. However, if they are only forming a trimer and not a long-chain polymer, this does not represent typical polymerization. Thus, this option does not represent polymerization in the conventional sense.

- **Option C**: Similar to option A, if it involves the polymerization of an alkene or alkyne, it would be a valid polymerization process.

- **Option D**: Again, if this option involves the polymerization of an alkene or alkyne, it would also be a valid polymerization process.

3. **Conclusion**:
- Based on the analysis, **Option B** does not represent polymerization of alkenes and alkynes, as it describes a trimer rather than a polymer.

### Final Answer:
**Option B** does not represent polymerization of alkenes and alkynes.