By definition, the correct answer is the second option: the reaction is a replacement.
A simple substitution reaction or simple displacement reaction, called single-displacement reaction, is a reaction in which an element of a compound is substituted by another element involved in the reaction.
The starting materials are always pure elements and an aqueous compound. And a new pure aqueous compound and a different pure element are generated as products.
The general form of a simple substitution reaction is:
AB + C → A +BC
where C and A are pure elements; C replaces A within compound AB to form a new co, placed CB and elementary A.
A single-displacement reaction is characterized by a place of exchange of cations or anions with another to form a new product. A begins as an ion in the solution and appears elementally in the reaction products. In case of reagent C it starts in its elemental form and ends as an ion in an aqueous state forming compound BC.
In this case, it is a single replacement reaction where 1 atom of Zinc metal displaces 2 H⁺ ions from the hydrochloric acid to form hydrogen gas and zinc chloride, a salt.
Finally, the correct answer is the second option: the reaction is a replacement.
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