The pair in which both the species have the same magnetic moment (spin only) is : [JEE Main 2020, 4 Sep (Shift 1)]

\(\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\) and \( \left[\mathrm{CoCl}_4\right]^{2-}\)

\(\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\) and \( \left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\)

\(\left[\mathrm{Mn}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\) and \( \left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\)

\(\left[\mathrm{Co}(\mathrm{OH})_4\right]^{2-}\) and \( \left[\mathrm{Fe}\left(\mathrm{NH}_3\right)_6\right]^{2+}\)