Concept:Ethene is a plant hormone that triggers fruit ripening.
Explanation:During ripening, fruits naturally produce ethene,
C2H4, which activates the enzymes needed for ripening.
Commercially, ethene gas is applied to fruits to speed up the ripening process.
Ethanol, ethyne, and ethane do not have this hormonal effect on fruits.
Therefore, ethene is the correct agent used to hasten ripening.
Answer:A. Ethene