external benefit or external cost

Consider each of the following activities or events and say for each one whether it creates an externality. Explain your answer. If so, say whether it creates an external benefit or external cost (negative) and whether the externality arises from production or consumption.
Airplanes take off from LaGuardia Airport during the US Open Tennis tournament, which is taking place nearby.
A sunset over the Pacific Ocean.- No Externality
An increase in the number of people who are studying for graduate degrees.
A person wears strong perfume to class.