Assertion : Blind spot is insensitive to both dim light and bright light so no image is formed on it.
Reason : Optic nerve arises from the blind spot.

Options

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

Answer

To solve the question, we need to evaluate the assertion and the reason provided:

### Step 1: Understand the Assertion
The assertion states that "Blind spot is insensitive to both dim light and bright light so no image is formed on it."
- The blind spot is a region on the retina where the optic nerve exits the eye.
- This area lacks photoreceptors (rods and cones), which are responsible for detecting light.
- Therefore, it is indeed insensitive to light, whether dim or bright, and no image can be formed there.

### Step 2: Understand the Reason
The reason states that "Optic nerve arises from the blind spot."
- This statement is true; the optic nerve does arise from the blind spot as it is the point where the nerve fibers from the retina converge and exit the eye.

### Step 3: Analyze the Relationship
Now, we need to determine if the reason is a correct explanation of the assertion.
- While both statements are true, the reason does not explain why the blind spot is insensitive to light. The insensitivity is due to the absence of photoreceptors, not merely because the optic nerve arises from that point.

### Step 4: Conclusion
Based on the analysis:
- The assertion is true.
- The reason is true, but it does not correctly explain the assertion.

Therefore, the correct answer is that both the assertion and reason are true, but the reason is not the correct explanation of the assertion.

### Final Answer:
**Option 2: Both assertion and reason are true, and reason is not the correct explanation of assertion.**

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