Given below are two statements: $\\$Statement I: Among $\left[\mathrm{Cu}\left(\mathrm{NH}_{3}\right)^{2+},\left[\mathrm{Ni}(\mathrm{en})_{3}\right)\right]^{2+}$, $\left[\mathrm{Ni}\left(\mathrm{NH}_{3}\right)_{6}\right]^{2+}$ and $\left[\mathrm{Mn}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+},\left[\mathrm{Mn}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}$, has the maximum number of unpaired electrons. $\\$Statement II: The number of pairs among $\left\{\left[\mathrm{NiCl}_{4}\right]^{2-},\left[\mathrm{Ni}(\mathrm{CO})_{4}\right]\right\},\left\{\left[\mathrm{NiCl}_{4}\right]^{2-},\left[\mathrm{Ni}(\mathrm{CN})_{4}\right]^{2-}\right.$ and $\left\{\left[\mathrm{Ni}(\mathrm{CO})_{4}\right], \quad\left[\mathrm{Ni}(\mathrm{CN})_{4}\right]^{2-}\right\}$ that contain only diamagnetic species is two. $\\$In the light of the above statements, choose the correct answer from the options given below: