The light pink color of $\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}$ and the deep blue color of $\left[\mathrm{CoCl}_{4}\right]^{2-}$ are due to
(a)MLCT transition in the first and d-d transition in the second
(b)LMCT transition in both
(c)d-d transitions in both.
(d)d-d transition in the first and MLCT transition in the second.