Assertion(A): The pressence of a catalyst increases the speed of the forward and backward reactions to the same extent.
Reason(R): Activation energy for both the forward and backward reactions is lowered to same extent.

Options

A. If both (A) and (R) are correct, and (R) is 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

Explanation

To solve the question, we need to analyze the assertion and reason provided regarding the effect of a catalyst on the speed of reactions.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that the presence of a catalyst increases the speed of both the forward and backward reactions to the same extent.
- This means that a catalyst does not favor one direction of the reaction over the other; it accelerates both processes equally.

2. **Understanding the Reason (R)**:
- The reason provided states that the activation energy for both the forward and backward reactions is lowered to the same extent by the catalyst.
- A catalyst works by providing an alternative reaction pathway with a lower activation energy, which applies equally to both the forward and backward reactions.

3. **Analyzing the Role of a Catalyst**:
- A catalyst does not change the overall energy change (ΔE) of the reaction; it only lowers the activation energy (Ea) required for the reaction to proceed.
- Since the catalyst lowers the activation energy for both the forward and backward reactions equally, the rates of these reactions are increased to the same extent.

4. **Conclusion**:
- Both the assertion and the reason are correct.
- The reason correctly explains why the assertion is true, as the catalyst lowers the activation energy for both reactions equally.

5. **Final Answer**:
- Therefore, the correct option is that both the assertion and reason are true, and the reason is the correct explanation of the assertion.