Spectroscopic ground state term symbols of cobalt ions in $\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}$ and $\left[\mathrm{CoCl}_{4}\right]^{2-}$ respectively are
(a)${}^{2}\mathrm{T}_{1\mathrm{g}}$ and ${}^{4}\mathrm{A}_{2}$
(b)${}^{4}\mathrm{T}_{1\mathrm{g}}$ and ${}^{4}\mathrm{A}_{2}$
(c)${}^{4}\mathrm{T}_{2\mathrm{g}}$ and ${}^{4}\mathrm{T}_{1}$
(d)${}^{2}\mathrm{T}_{1}$ and ${}^{4}\mathrm{A}_{1}$