Given below are some of the statements about Mn and $\mathrm{Mn}_2 \mathrm{O}_7$. Identify the correct statements. A. Mn forms the oxide $\mathrm{Mn}_2 \mathrm{O}_7$, in which Mn is in its highest oxidation state. B. Oxygen stabilizes the Mn in higher oxidation states by forming multiple bonds with Mn . C. $\mathrm{Mn}_2 \mathrm{O}_7$ is an ionic oxide. D. The structure of $\mathrm{Mn}_2 \mathrm{O}_7$ consists of one bridged oxygen. Choose the correct answer from the options given below :