Step 1: Identify the reactants and products for each reaction. For (b) C, the reactants are carbon (C) and water (H2O), and the products are hydrogen gas (H2) and carbon monoxide (CO). For (c) CH4, the reactants are methane (CH4) and water (H2O), and the products are hydrogen gas (H2) and carbon monoxide (CO). For (d) H2O, the reactants are water (H2O) and a source of energy, and the products are hydrogen gas (H2) and oxygen gas (O2).