The correct option is A In covalent compounds fluorine can form single bond while oxygen forms double bond
The ability of oxygen to stabilise the higher oxidation state is more than that of fluorine. Also, the ability of oxygen to form multiple bonds with metal favours Mn2O7. Therefore, the highest fluoride of Mn is MnF4 whereas highest oxide is Mn2O7. In Mn2O7, each Mn is tetrahedrally surrounded by Os including an Mn−O−Mn bridge.