Assertion : In the extraction of Ag, complex `Na[Ag(CN)_(2)]` is reacted with Zn.
Reason : Zn is d-block transition metal.

Options

A. If both assetion and reason are CORRECT, and reason is the CORRECT explanation of the assertion
B. If both assertion and reason are CORRECT, but reason is NOT the CORRECT explanation of the assertion
C. If assertion is CORRECT but reason is INCORRECT
D. If assertion is INCORRECT but reason is CORRECT

Answer

To solve the question regarding the assertion and reason about the extraction of silver (Ag) using the complex Na[Ag(CN)₂] and zinc (Zn), we will analyze each part step by step.

### Step 1: Analyze the Assertion
The assertion states that in the extraction of silver, the complex Na[Ag(CN)₂] is reacted with zinc.

- **Explanation**: In the extraction process, silver is typically obtained from its cyanide complex. The complex Na[Ag(CN)₂] is a soluble complex formed when silver is treated with sodium cyanide. When zinc is added to this complex, a displacement reaction occurs. Zinc, being more reactive than silver, displaces silver from the complex, leading to the formation of sodium zinc cyanide (Na₂Zn(CN)₄) and elemental silver (Ag).

### Step 2: Analyze the Reason
The reason states that zinc is a d-block transition metal.

- **Explanation**: Zinc (Zn) is indeed classified as a d-block element because it is found in the d-block of the periodic table. However, it is important to note that zinc does not qualify as a transition metal. Transition metals are defined as elements that have an incomplete d-subshell in at least one of their oxidation states. Zinc has a full d-subshell (3d¹⁰) in its most common oxidation state (+2), which means it does not have any unpaired electrons and does not exhibit typical transition metal properties.

### Step 3: Conclusion
- **Assertion**: Correct (The reaction of Na[Ag(CN)₂] with Zn does occur and leads to the extraction of silver).
- **Reason**: Incorrect (While zinc is a d-block element, it is not classified as a transition metal due to its fully filled d-orbitals).

### Final Answer
Thus, the correct conclusion is that the assertion is true, but the reason is false.