The following word equation describes a chemical reaction in which hydrogen is produced. magnesium + hydrochloric acid - magnesium chloride + hydrogen What is the source of the atoms in the hydrogen gas produced by this reaction?

Question

$\begin{array}{1 1} (a)\; magnesium \\ (b)\; hydrochloric\; acid \\ (c)\; Sodium \\ (d)\; Hydrogen \end{array}$