The correct statement about iron includes (I) the highest oxidation state of iron is +6 in K2FeO4 (II) that the iron shows +2 oxidation state with six electrons in the 3d orbitals (III) the common oxidation state of iron is +3 with five unpaired electrons in the 3d orbital
a. I, II, III
b. I, II
c. II, III
d. I only