Concept:An option is a contract that gives the right to buy or sell a security within a fixed period.Explanation:In the stock exchange, an option allows an investor to buy or sell shares at a stated price before a given date.The holder has the right, but not the obligation, to complete the deal.This means the investor may choose whether to exercise the option or let it expire.So, the correct term for this right is "option".Answer:A. option