Which species of vanadium has a different oxidation number from the rest?

A.     \({\text{VO}}_2^ + \)

B.     \({\text{VO}}_3^ - \)

C.     \({{\text{V}}_{\text{2}}}{{\text{O}}_{\text{5}}}\)

D.     \({\text{V}}{{\text{O}}^{2 + }}\)

D