Answer: to a firm by government that prevents other firms from producing the same product or service
Explanation:
A public franchise is a right granted to a firm by government that prevents other firms from producing the same product or service.
This is done by the government in a situation whereby the government doesn't want a competition for the firm or doesn't want other firms to sell that particular good.
For example, if a particular firm comes up with a drug that can cure HIV/AIDS, the government may grant such firm a public franchise.