Which of the following is an example of a positive externality? Group of answer choices permitting smoking on commercial airplanes raising the speed limit to 60 mph in school zones planting trees along a sidewalk which add beauty and create shade a police department stops enforcing DUI laws

Brian has just finished college. he wants to set up a small business to make and sell fireworks. he registers his company and acquires a license from the government. he finds that most of his competitors are selling fireworks at an extremely low price. he would like to make more money, so he decides to innovate and develop better fireworks. he sells his fireworks at a higher price, and they are a huge hit with the customers. after a few years, he earns enough profit to set up a bigger fireworks factory that complies with the government’s health and safety regulations. he even starts exporting fireworks overseas. which type of economy does this scenario describe?