The correct option is D Cu2O
In KMnO4, Mn has a oxidation state of +7 therefore doesn't have any electron in d orbital which implies there is no d-d transition in KMnO4 and colour will appear due to ligand to metal charge transfer spectra.
Similarly, in CrO3, Cr has a oxidation state of +6 therefore doesn't have any electron in d orbital which implies there is no d-d transition in CrO3 and colour will appear due to ligand to metal charge transfer spectra.
In case of CuCl2,Cu has a oxidation state of +2 and Cu has d9 electronic configuration and therefore d-d transition can take place.
In last option Cu2O has oxidation state of +1 which recommend d10 electronic configuration for Cu2O and therefore there is no d-d transition in Cu2O.
Hence colour is arised in A, B, D due to charge transfer spectra.