In which of the following pairs of molecules/ions, the central atoms have $s{p}^2$ hybridization?

1. A
   ${\text{BF}}_3$ and ${\text{NH}}_2^{-}$
2. B
   ${\text{NO}}_2^{-}$ and ${\text{NH}}_3$
3. C
   ${\text{BF}}_3$ and ${\text{NO}}_2^{-}$
4. D
   ${\text{NH}}_2^{-}$ and ${\text{H}}_2\text{O}$