How does having a patent give a company a monopoly? A. A patent is a contract issued by a local authority that gives a single firm the right to sell its goods within an exclusive market. B. A patent gives firms the right to operate a business, especially where scarce resources are involved. C. A patent gives a company exclusive rights to sell a new good or service for a period of time. D. A patent allows the companies in an industry to restrict the number of firms in a