`C_(2)H_(5)OHoverset(X)rarrC_(2)H_(5)Cl`
X can be except `:`

Options

A. `SOCl_(2)`
B. `PCl_(3)`
C. `PCl_(5)`
D. `NaCl`

Explanation

To solve the question, we need to identify which reagents (X) can convert ethanol (C₂H₅OH) into ethyl chloride (C₂H₅Cl) and which cannot.

### Step-by-Step Solution:

1. **Identify the Reaction**: We are looking for a reagent (X) that can convert ethanol (C₂H₅OH) into ethyl chloride (C₂H₅Cl).

2. **Consider the First Reagent: SOCl₂ (Thionyl Chloride)**:
- Reaction:
\[ C₂H₅OH + SOCl₂ \rightarrow C₂H₅Cl + SO₂ + HCl \]
- This reaction produces ethyl chloride along with sulfur dioxide and hydrogen chloride. Therefore, SOCl₂ can be used.

3. **Consider the Second Reagent: PCl₃ (Phosphorus Trichloride)**:
- Reaction:
\[ C₂H₅OH + PCl₃ \rightarrow C₂H₅Cl + H₃PO₃ \]
- This reaction also produces ethyl chloride and phosphorous acid. Hence, PCl₃ can be used.

4. **Consider the Third Reagent: PCl₅ (Phosphorus Pentachloride)**:
- Reaction:
\[ C₂H₅OH + PCl₅ \rightarrow C₂H₅Cl + POCl₃ + HCl \]
- This reaction results in the formation of ethyl chloride, along with phosphorous oxychloride and hydrogen chloride. Thus, PCl₅ can also be used.

5. **Consider the Fourth Reagent: NaCl (Sodium Chloride)**:
- Reaction:
\[ C₂H₅OH + NaCl \rightarrow C₂H₅ONa + HCl \]
- In this case, the reaction produces an alkoxide ion (C₂H₅ONa) and does not yield ethyl chloride. Therefore, NaCl cannot be used.

6. **Conclusion**: The reagent (X) that cannot convert ethanol to ethyl chloride is NaCl.

### Final Answer:
X cannot be NaCl.