In these question, a statement of assertion followed by a statement of reason is given .Choose the correct answer out of the following choices:
Assertion and reason both are correct statements and reason is correct explanation for assertion.
Assertion and reason both are correct statements but reason is not correct explanation for assertion.
Assertion is correct statement but reason is wrong statement.
Assertion is wrong statement but reason is correct statement.
Assertion: in optical fibre, the diameter of the core is kept small.
Reason: This smaller diameter of the core ensures that the fibre should have incident angle more than the critical angle required for total internal reflection.

Options

A. A
B. B
C. C
D. D