Assertion : A solution of `AgCI` in `NH_(4)OH` gives a white prrecipitate when acidified with `NHO_(3)`
Reasion : `[Ag(NH_(3))_(2)]^(o+)` decompoes in the presence of `HNO_(3)`

Options

A. If both (A) and (B) are correct and (R ) is the correct explqanation of (A)
B. If both (A) and (B) are correct but (R ) is not the correct explqanation of (A)
C. If (A) is correct ,but (R ) is incorrect
D. If (A) is incorrect ,but (R ) is correct

Explanation

To solve the given question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that a solution of AgCl in NH4OH gives a white precipitate when acidified with HNO3.
- AgCl (silver chloride) is a sparingly soluble salt that can dissolve in ammonia (NH4OH) to form a complex ion.

2. **Reaction of AgCl with NH4OH**:
- When AgCl is treated with NH4OH, it forms a complex ion:
\[ \text{AgCl} + 2 \text{NH}_3 \rightarrow [\text{Ag(NH}_3)_2]^+ + \text{Cl}^- \]
- This complex ion, \([\text{Ag(NH}_3)_2]^+\), is soluble in the solution.

3. **Acidification with HNO3**:
- When the solution is acidified with HNO3 (nitric acid), the complex ion decomposes:
\[ [\text{Ag(NH}_3)_2]^+ + \text{H}^+ \rightarrow \text{Ag}^+ + \text{NH}_4^+ \]
- This reaction releases Ag+ ions into the solution.

4. **Formation of Precipitate**:
- The released Ag+ ions then react with the chloride ions (Cl-) present in the solution:
\[ \text{Ag}^+ + \text{Cl}^- \rightarrow \text{AgCl} \downarrow \]
- This results in the formation of a white precipitate of AgCl.

5. **Conclusion about the Assertion**:
- The assertion is correct because the reaction indeed leads to the formation of a white precipitate of AgCl when the solution is acidified.

6. **Understanding the Reason**:
- The reason states that \([\text{Ag(NH}_3)_2]^+\) decomposes in the presence of HNO3.
- This is also correct, as we have shown that the complex ion decomposes to release Ag+ ions upon acidification.

7. **Final Conclusion**:
- Both the assertion and the reason are correct, and the reason correctly explains the assertion.

### Final Answer:
- The assertion is true, and the reason is true; the reason is a correct explanation of the assertion.