Assertion : Ubiquinone is non - protein coenzyme.
Reason : Ubiquinone acts as an activator in ETS.

Options

A. If both Assertion and Reason are true and Reason is correct explanation of Assertion.
B. If both Assertion and Reason are true but Reason is not a correct explanation of Assertion.
C. If Assertion is true but Reason is false.
D. If both Assertion and Reason are false.

Answer

To solve the question regarding the assertion and reason about Ubiquinone, we need to analyze both statements carefully.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Ubiquinone is a non-protein coenzyme."
- This is true. Ubiquinone, also known as coenzyme Q10, is indeed a non-protein coenzyme that plays a crucial role in the electron transport chain (ETS) within the mitochondria.

2. **Understanding the Reason**:
- The reason states that "Ubiquinone acts as an activator in ETS."
- This statement is misleading. While Ubiquinone is involved in the electron transport chain, it does not act as an activator. Instead, it functions as an electron carrier, transferring electrons between various complexes in the ETS. Therefore, this statement is false.

3. **Evaluating the Options**:
- Now we need to evaluate the options based on our analysis:
- **Option 1**: Both the assertion and reason are true, and the reason is a correct explanation of the assertion. (Incorrect)
- **Option 2**: Both assertion and reason are true, but the reason is not a correct explanation of the assertion. (Incorrect)
- **Option 3**: Assertion is true, and reason is false. (Correct)
- **Option 4**: Both assertion and reason are false. (Incorrect)

4. **Conclusion**:
- The correct answer is **Option 3**: Assertion is true, and reason is false.