Shape of ${\mathrm{NH}}_3$ is very similar to:

Both ${\mathrm{NH}}_3$ and ${\mathrm{CH}}_3^{-}$ are pyramidal.

N in ${\mathrm{NH}}_3$ and C in ${\mathrm{CH}}_3^{-}$​ both have ${\mathrm{sp}}^3$ hybridization with one lone pair of electron on each.

Thus, the option B is correct.