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)

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