Assertion : The rate of a reaction sometimes does not depend on concentration.
Resaon : Lower the activation energy, faster is the reaction

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that the rate of a reaction sometimes does not depend on concentration. This is true for zero-order reactions, where the rate of reaction is constant and does not change with the concentration of reactants.

2. **Example of Zero-Order Reaction**:
- For a zero-order reaction, the rate equation can be expressed as:
\[ \text{Rate} = k[A]^0 = k \]
- Here, \( k \) is the rate constant, and since \( [A]^0 = 1 \), the rate is independent of the concentration of reactant A.

3. **Understanding the Reason**:
- The reason states that lower activation energy results in a faster reaction. This is also true because activation energy is the minimum energy required for reactants to undergo a chemical reaction. A lower activation energy means that more molecules have the energy to react, leading to an increased rate of reaction.

4. **Connecting Assertion and Reason**:
- While both the assertion and reason are correct, the reason does not explain the assertion. The assertion is about the dependency of reaction rate on concentration, while the reason discusses the effect of activation energy on reaction rate.

5. **Conclusion**:
- Since both the assertion and reason are true, but the reason does not provide a justification for the assertion, the correct answer is that both statements are true, but the reason is not the correct explanation of the assertion.

### Final Answer:
- The correct option is: Both assertion and reason are true, but reason is not the correct explanation of assertion.

---