Consider the reaction represented by the following equation: N_2(g) + 3H_2(g) ⇌ 2NH_3(g); ∆H = - 92kJmol¹. Finely divided iron is used as catalyst in the reaction in order to

• A lower the value of ∆H
• B increase the time for attainment of equilibrium
• C shorten the time for attainment of equilibrium
• D decrease the yield of ammonia