Answer:
D. a firm designated by the government as the only legal provider of a good or service.
Step-by-step explanation:
Public franchise -
It is the type of firm , which is legally opened by the government , to provide certain goods and services, is referred to as public franchise.
These firm are opened in order to restrict the market , as , where other any other firm are not allowed to compete .
This method is adapted in order to regulate the market , which helps the consumers to buy certain products at lower price .