d
The value of \(n_{e}\) in the doped semiconductor is

\(n _{ e } n _{ h }= n _{ i }^{2}\)

\(n _{e}=\frac{ n _{ i }^{2}}{ n _{ h }}\)

\(n _{ e }=\frac{\left(10^{16} m ^{-3}\right)^{2}}{\left(5 \times 10^{22} m ^{-3}\right)}=2 \times 10^{9} m ^{-3}\)