A stationary $He^+$ ion emitted a photon corresponding to the first line $(H_{\alpha})$ of the Lyman series .That photon liberated a photo electron from a stationary H atom in ground state.What is the velocity of photo electron?$R_H=109678cm^{-1}$

Question

$\begin{array}{1 1}(a)\;2.03\times 10^8cm/s&(b)\;3.09\times 10^8cm/s\\(c)\;3.09\times 10^2cm/s&(d)\;1.03\times 10^8cm/s\end{array}$