Q. Pick out the wrong statement.

(A) Addition of methane to the furnace atmosphere reduces decarburising by hydrogen

(B) Nitrogen in presence of steam decar-burises high carbon steel, whereas hydrocarbon gases carburise the surface of steel at annealing temperatures

(C) Active nitrogen (formed by cracking ammonia at the metal surface) cause nitride formation with increase in surface hardness

(D) None of these