Statement : Number of waves in an orbit of atom is equal to number of that orbit .
Explanation : Number of waves in an robit is derived by ` ( 2 pir_n)/(lambda)`.
A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false
D. If assertion is false but reason is true.