Which is correct geometry in the case of ${\left[{\mathrm{NiCl}}_4\right]}^{2-}$ complex?

Which of the following compound is square planar and does not have any unpaired electron:

(a) ${\left[\mathrm{Cu}{\left({\mathrm{NH}}_3\right)}_4\right]}^{+2}$ (b) ${\mathrm{XeF}}_4$ (c) $\left[\mathrm{Ni}(\mathrm{CO}{)}_4\right]$ (d) ${\left[{\mathrm{NiCl}}_4\right]}^{-2}$ (e) ${\left[\mathrm{Ni}(\mathrm{CN}{)}_4\right]}^{-2}$ (f) ${\mathrm{CuSO}}_4.5{\mathrm{H}}_2\mathrm{O}$