Correct Answer - C
For `sp^2`-hyridization, the `SN` of the central atom should be 3. `SN` of `B`(in `BF_3`) is `3+0=3`, `SN` of `N`(in `NO_2^(-)`) is `2+1=3`, `SN` of `N` (in `NH_2^(-)`) is `2+2=4`, and `SN` of `O` in `(H_2O)` is `2+2=4`. Thus, in both `BF_3` and `NO_2^(-)`, the central atom is `sp^2`-hybridized.