The $\lambda$ of $H_{\alpha}$ line of Balmer series is $6500A^{\large\circ}$.What is the $\lambda$ of $H_{\beta}$ line of Balmer series?

Question

$\begin{array}{1 1}(a)\;4814.8A^{\large\circ}&(b)\;3426.7A^{\large\circ}\\(c)\;5234A^{\large\circ}&(d)\;3672.6A^{\large\circ}\end{array}$