A strong field ligand will enable higher crystal field splitting. It can be predicted from the relative position of a ligand in spectrochemical series. In the given octahedral complexes of Cr(II) ion, the ligands are F−,H2O,NH3 and CN− and their increasing order of field strength in spectrochemical series is F−<H2O<NH3<CN− So, highest octahedral crystal field splitting is present in [