Upon reaction of zinc with dilute hydrochloric acid, the following equation represents the process:
\[
\text{Zn} + 2\text{HCl} \to \text{ZnCl}_2 + \text{H}_2
\]
The gas liberated in this reaction is hydrogen (\(\text{H}_2\)).
Answer: Hydrogen gas is the product, thus option (2) is the correct selection.