In a direct $pn$ junction with internal quantum efficiency of $70\%.$ Assuming that the sample has $N_A=4\mathrm{.}37{10}^{16}c{m}^{-3}$ and $N{b}_b=4\mathrm{.}37{10}^{i9}c{m}^{-3}$ where $6\mathrm{.}24{10}^{18}$ electrons recombine with holes every second. The number of emith thatotons per second is:

$($a$)8\mathrm{.}91{10}^{18}$

$($b$)4\mathrm{.}37{10}^{18}$

$($c$)3\mathrm{.}01{10}^{16}$

$($d$)6\mathrm{.}24{10}^{16}$