In the given reaction
`C_(2)H_(5)-O-overset(O)overset(||)C-O-C_(2)H_(5)+HO-CH_(2)-CH_(2)-OH overset(H^(o+))to [X],[X]` is

Options

A. `C_(2)H_(5)-O-overset(O)overset(||)C-O-CH_(2)-CH_(2)-OH`
B. `HO-CH_(2)-CH_(2)-O-O-overset(O)overset(||)C-O-CH_(2)-CH_(2)-OH`
C.
D. No reaction is possible

Answer

To solve the given reaction step by step, we need to analyze the reactants and the conditions provided. The reaction involves an ester and ethylene glycol in the presence of an acid catalyst (H⁺).

### Step-by-Step Solution:

1. **Identify the Reactants**:
The reactants are:
- An ester: C₂H₅-O-CO-O-C₂H₅ (diethyl carbonate)
- Ethylene glycol: HO-CH₂-CH₂-OH

2. **Understand the Reaction Type**:
The reaction is a nucleophilic substitution reaction where ethylene glycol acts as a nucleophile. The presence of H⁺ indicates that the reaction is acid-catalyzed.

3. **Nucleophilic Attack**:
The hydroxyl group (-OH) from ethylene glycol will attack the carbonyl carbon (C=O) of the ester. This will lead to the formation of a tetrahedral intermediate.

4. **Formation of Tetrahedral Intermediate**:
When the nucleophile attacks, the double bond (C=O) breaks, and the oxygen becomes negatively charged. The structure at this stage will have:
- C₂H₅-O- (ethyl group)
- A negatively charged oxygen
- The ethylene glycol structure attached.

5. **Rearrangement and Elimination**:
After the formation of the tetrahedral intermediate, the negatively charged oxygen will facilitate the departure of one of the ethyl groups (C₂H₅O⁻). This results in the formation of a new compound.

6. **Final Product Formation**:
The final product will be a new ester formed from the remaining components:
- The remaining ethylene glycol structure (with one -OH group)
- The ethyl group that was not eliminated.

The final product can be represented as:
- HO-CH₂-CH₂-O-C(=O)-C₂H₅ (which is ethyl glycolate).

### Conclusion:
The final product [X] is ethyl glycolate, which can be represented as HO-CH₂-CH₂-O-C(=O)-C₂H₅.