The highest oxidation state of manganese in fluorides is 4 (MnF₄), but the highest oxidation state in oxides is 7 (Mn₂O₇) because:
a) Fluorides are more electronegative than oxides.
b) Fluorine can stabilize higher oxidation states.
c) Oxides have a different coordination environment.
d) Fluorides exhibit stronger bonding with manganese.