`CH_3C-=C CH underset((ii)H_2O // Zn)overset((i)X)to CH_3-undersetunderset(O)(||)C-undersetunderset(O)(||)C-CH_3`
X in the above reaction is

Options

A. `HNO_3`
B. `O_2`
C. `O_3`
D. `KMnO_4`

Explanation

To solve the problem, we need to identify the reagent X in the given reaction involving the transformation of an alkyne to a ketone using water and zinc. The reaction can be broken down into steps as follows:

### Step-by-Step Solution:

1. **Identify the Starting Material:**
The starting material is CH₃C≡CCH₃, which is 2-butyne.

2. **Understand the Reaction Conditions:**
The reaction is performed in the presence of H₂O and Zn. This indicates that the reaction is likely a form of hydration of the alkyne.

3. **Recognize the Type of Reaction:**
The reaction described is a form of ozonolysis, specifically reductive ozonolysis. In this reaction, the triple bond of the alkyne is cleaved, and the resulting fragments are converted into carbonyl compounds (ketones).

4. **Determine the Product:**
The expected product from the reaction of 2-butyne with H₂O and Zn is dimethylglyoxal (DMG), which has the structure CH₃C(=O)C(=O)CH₃.

5. **Identify the Reagent X:**
In the context of ozonolysis, the reagent X that is commonly used is ozone (O₃). Therefore, in this reaction, X is ozone.

### Final Answer:
X in the above reaction is ozone (O₃).

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