Highest oxidation state of Mn is exhibited in \( \mathrm{Mn_2O_7} \). The correct statements about \( \mathrm{Mn_2O_7} \) are
(A) Mn is tetrahedrally surrounded by oxygen atoms
(B) Mn is octahedrally surrounded by oxygen atoms
(C) Contains Mn-O-Mn bridge
(D) Contains Mn-Mn bond
Choose the correct answer from the option given below: