The photon capable of removing electron from I Bohr's orbit must posses energy
= 13.6 eV
= $13.6\times1.602\times10^{-19}$J
= $21.787\times10^{-19}$ J
E = $\large\frac{h\times c}{\lambda}$
$21.787\times10^{-19}$ = $\large\frac{6.625\times10^{-34}\times3.0\times10^8}{\lambda}$
$\lambda = 912.24\times10^{-10}$ m
= 912.24 $\overset{\circ}{A}$
Hence the answer is (c)