Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): Refractive index of glass is higher than that of air.

Reason (R): Optical density of a medium is directly proportionate to its mass density which results in a proportionate refractive index.

In the light of the above statements, choose the most appropriate answer from the options given below:

1. A <p>Both (A) and (R) are correct and (R) is the correct explanation of (A)</p>
2. B <p>(A) is correct but (R) is not correct</p> Correct answer
3. C <p>(A) is not correct but (R) is correct</p>
4. D <p>Both (A) and (R) are correct but (R) is <b>not</b> the correct explanation of (A)</p>