Answer:
is less than the marginal social benefit of roses
Step-by-step explanation:
A good has positive externality if the benefits to third parties not involved in production is greater than the cost. A good has positive externality if the price of the good is less than its marginal social benefit. an example of an activity that generates positive externality is research and development. Due to the high cost of R & D, they are usually under-produced. Government can encourage the production of activities that generate positive externality by granting subsidies.
A good has negative externality if the price of the good is less than the marginal social cost of the good