Match Column I with Column II for the oxidation states of the central atoms.

Option (i) Cr₂O₇^2-→ (d) +6

By oxidation rule we can calculate the unknown oxidation number.

Cr₂O₇^2-

Option (ii) MnO^-₄→ (e) +7

MnO^-₄

Option (iii) VO^-₃→ (c) +5

VO^-₃

Option (iv) FeF^3-₆→ (a) +3

FeF^3-₆