The first emission line of hydrogen atomic spectrum in the Balmer series appears at (R = Rydberg constant) :

Question

( A ) $\frac{7R}{36}cm^{-1}$
( B ) $\frac{5R}{36}cm^{-1}$
( C ) $\frac{9R}{400}cm^{-1}$
( D ) $\frac{3R}{4}cm^{-1}$