In which complexes does iron have an oxidation number of  $+ 3$?

I.     ${{\text{[Fe(}}{{\text{H}}_2}{\text{O}}{{\text{)}}_6}{\text{]}}^{3 + }}$

II.     ${{\text{[Fe(}}{{\text{H}}_2}{\text{O}}{{\text{)}}_5}{\text{(CN)]}}^{2 + }}$

III.     ${{\text{[Fe(CN}}{{\text{)}}_6}{\text{]}}^{3 - }}$

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

D