$\mathrm{KMnO}{}_4$ is deep purple although the manganese in $\mathrm{MnO}{}_4{}^{-}$ has no d electrons. Which description is correct?

1. AMn is +7 ($d^0$) and the colour arises from d-d transitions
2. BMn is +7 ($d^2$) and the colour arises from charge transfer
3. CMn is +7 ($d^0$, diamagnetic) and the colour arises from ligand-to-metal charge transfer from O to Mn
4. DMn is +6 ($d^1$, paramagnetic) and the colour arises from d-d transitions