Liquid ammonia undergoes autoionisation. Which option gives the ions formed and the strongest base that can persist in liquid ammonia?

1. A$\mathrm{NH}{}_4{}^{+}$ and $\mathrm{NH}{}_2{}^{-}$; the strongest base is $\mathrm{NH}{}_2{}^{-}$
2. B$\mathrm{NH}{}_4{}^{+}$ and $\mathrm{NH}{}_2{}^{-}$; the strongest base is $\mathrm{OH}{}^{-}$
3. C$\mathrm{H}{}^{+}$ and $\mathrm{NH}{}_2{}^{-}$; the strongest base is $\mathrm{H}{}^{-}$
4. D$\mathrm{NH}{}_3{}^{+}$ and $\mathrm{NH}{}^{-}$; the strongest base is $\mathrm{NH}{}^{-}$