Assertion(A): Catalysts are aways transition metals.
Reason(R): Trasition metals have varitable oxidation state.

Options

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

Answer

To analyze the given assertion and reason, we can break down the problem into several steps:

### Step 1: Understand the Assertion
**Assertion (A)**: Catalysts are always transition metals.

- **Explanation**: This statement suggests that all catalysts belong to the category of transition metals. However, this is not entirely accurate, as there are catalysts that are not transition metals, such as certain enzymes (biological catalysts) and some non-metals.

### Step 2: Understand the Reason
**Reason (R)**: Transition metals have variable oxidation states.

- **Explanation**: This statement is true. Transition metals are known for their ability to exhibit multiple oxidation states due to their d-orbitals. This property allows them to participate in various chemical reactions, making them effective catalysts.

### Step 3: Evaluate the Relationship Between Assertion and Reason
- The assertion claims that all catalysts are transition metals, which is incorrect. While many catalysts are transition metals due to their variable oxidation states, not all catalysts fall into this category.
- The reason provided is correct, as the variable oxidation states of transition metals do contribute to their catalytic properties.

### Conclusion
- Since the assertion is false and the reason is true, the correct relationship is that the reason does not adequately explain the assertion.

### Final Answer
The assertion is false, and the reason is true. Therefore, the correct answer is that the assertion and reason are not both correct.

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