c
\([Ni(CN)]^{2-}\) is square planar, diamagnetic (\(0\) unpaired electrons) with \(dsp^2\) hybridisation.\([Ni(CO)_4] -\) is tetrahedral,diamagnetic (\(0\) unpaired electrons) with \(sp^3\) hybridisation. \([NiCl_4]^{2-}\) is tetrahedral, paramagnetic (\(2\) unpaired electrons) with \(sp^3\) hybridisation.Hence, the option \((c)\) is the correct answer