`Bu-C=CHoverset(LiNH_2)toAunderset((ii)H_2O)overset((i)PhCHO)toBoverset(MnO_2)toC`
Compound C of the above reaction cannot be :

Options

A.
B.
C.
D.

Explanation

To solve the question regarding the transformation of the compound Bu-C≡CH through a series of reactions, we will break down each step and identify the final product C, while also determining which compound cannot be C.

### Step-by-Step Solution:

1. **Starting Compound**:
- We begin with Bu-C≡CH (but-1-yne).

2. **Reaction with LiNH₂ and H₂**:
- When Bu-C≡CH is treated with lithium amide (LiNH₂) and hydrogen (H₂), the terminal alkyne hydrogen is replaced by a lithium ion, resulting in the formation of a lithium acetylide.
- This gives us Compound A: Bu-C≡C⁻Li⁺.

3. **Reaction with PhCHO (Benzaldehyde)**:
- The lithium acetylide (C≡C⁻) acts as a nucleophile and attacks the carbonyl carbon of benzaldehyde (PhCHO), leading to the formation of an alkoxide intermediate.
- This results in Compound B: Ph-CH(OH)-C≡C-Bu.

4. **Hydrolysis with H₂O**:
- The alkoxide intermediate is then treated with water (H₂O), which protonates the alkoxide, yielding an alcohol.
- Thus, Compound B becomes: Ph-CH(OH)-C≡C-Bu.

5. **Oxidation with MnO₂**:
- The alcohol (Ph-CH(OH)-C≡C-Bu) is then oxidized using manganese dioxide (MnO₂), converting the alcohol into a ketone.
- This results in Compound C: Ph-C(=O)-C≡C-Bu.

### Conclusion:
Now, we need to identify which compound cannot be Compound C.

- **Possible Structures for Compound C**:
- The structure of Compound C is expected to have a phenyl group (Ph), a carbonyl group (C=O), and a terminal alkyne (C≡C) connected to butyl (Bu).

- **Analysis of Options**:
- If any of the options provided in the question include a structure that has:
- An aldehyde group (CHO) instead of a ketone (C=O).
- Any other functional group that does not match the expected structure of Compound C.

From the analysis, we conclude that Compound C cannot have an aldehyde group (CHO) attached to it, as it must have a ketone functional group.

### Final Answer:
Compound C of the above reaction cannot be **CHO - C≡C - Bu** (or any structure that includes an aldehyde instead of a ketone).