b
In the ground state energy \(=-13.6\,eV\)

So energy

\(\quad \frac{-13.6 eV }{n^2}=-13.6+12.75\)

\(\frac{-13.6 eV }{n^2}=-0.85\)

\(\quad n=\sqrt{16}\)

\(\qquad n=4\)

\(\text { Angular momentum }=\frac{n h}{2 \pi}=\frac{4 h}{2 \pi}=\frac{2 h}{\pi}\)

\(\text { Angular momentum }=\frac{2}{\pi} \times 4.14 \times 10^{-15}\)

\(\qquad=\frac{828 \times 10^{-17}}{\pi} eVs\)