Choose correct options from statements below about the enzyme nitrogenase

I. can be found in most bacteria and a few invertebrate animals.
II. contains unique redox centers that contain both Fe and Mo.
III. changes in conformation as a result of ATP hydrolysis.
IV. carries out a reaction that reduces nitrogen to NO.

(a) I, II, III, IV
(b) II, III, IV
(c) II, III
(d) III, IV
(e) IV only