Analyzing each statement:
Statement A: In Mn₂O₇, using oxidation state calculation: 2(Mn) + 7(O⁻²) = 0, so Mn oxidation state = +7. This is indeed the highest oxidation state for Mn. TRUE.
Statement B: Oxygen stabilizes Mn in +7 oxidation state through multiple bonding (Mn=O double bonds and bridging), reducing electron density effectively. TRUE.
Statement C: Mn₂O₇ is primarily a covalent oxide with significant Mn-O covalent bonding character. The oxide is not ionic in nature. FALSE.
Statement D: The structure of Mn₂O₇ contains bridged oxygen atoms (Mn-O-Mn linkages) along with terminal Mn=O bonds. TRUE.
Statements A, B, and D are correct while C is incorrect. The answer is option (1): A, B and D Only.