`A overset("Kolbe's electrolysis")rarr` propyne will be

Options

A. `CH_(3)-CH_(2)-CH_(2)-COOK`
B. `underset(COOK)underset(|)(CH_(3))-underset(COOK)underset(|)(CH)-CH_(3)`
C. `underset(COOK)underset(|)(CH)-underset(COOK)underset(|)(C)-CH_(3)`
D. `underset(COOK)underset(|)(CH_(2))-CH-CH_(2)`

Answer

To solve the question regarding Kolbe's electrolysis and its relation to propyne production, we will follow a systematic approach.

### Step-by-Step Solution:

1. **Understand Kolbe's Electrolysis**:
Kolbe's electrolysis involves the electrolysis of carboxylic acid salts (typically potassium salts) which leads to the formation of radicals. These radicals can couple together to form alkenes or alkynes, depending on the structure of the starting material.

2. **Identify the Product**:
We need to find a reactant that, when subjected to Kolbe's electrolysis, produces propyne (C3H4).

3. **Analyze the Given Options**:
We will evaluate each option to see which one can produce propyne.

- **Option A**:
- Structure: CH3CH2CH2COOK
- Upon electrolysis, this compound produces CH3CH2CH2 radicals, which couple to form hexane (C6H14).
- **Conclusion**: This does not yield propyne.

- **Option B**:
- Structure: CH3CH3COOK
- Electrolysis produces CH3CH radicals, which couple to form an alkene (C3H6).
- **Conclusion**: This does not yield propyne.

- **Option C**:
- Structure: CH3CH2COOK
- Electrolysis produces CH3C radical, which when coupled forms propyne (C3H4).
- **Conclusion**: This yields propyne.

- **Option D**:
- Structure: CH2COOK
- Electrolysis produces CH2 radical, which does not lead to the formation of propyne.
- **Conclusion**: This does not yield propyne.

4. **Final Conclusion**:
The only option that leads to the formation of propyne is **Option C** (CH3CH2COOK).

### Final Answer:
The reactant A that undergoes Kolbe's electrolysis to produce propyne is **Option C**.