Commercial scale production of hydrogen from iron-steam reaction represented by, 3Fe + 3H2O = Fe3O4 + 4H2, is not practised, as it is

• A. a slow reaction.
• B. a discontinuous reaction (requiring regeneration of iron by water gas intermittently).
• C. still in development stage (by employing fluidised bed technique).
• D. all (a), (b) and (c).