Reаctiоn A CH4(g) + 2O2(g) → CO2(g) + 2H2O(l)Reаctiоn B Mg(s) + 2HCl(аq) → MgCl2(aq) + H2(g)Reactiоn C AgNO3 + NaCl → AgCl + NaNO3 Reaction D HCl + NaOH → NaCl + H2OReaction E N2(g) + 3H2(g) → 2NH3(g)Identify the combination reaction. Calculate the oxidation state of nitrogen in the product.