My neighbor ________ is an example of an external benefit.

A) smoking a cigarette in my presence
B) playing loud music on his radio that I can hear
C) dumping hazardous chemicals on a stream that passes through my property
D) keeping the leaves from his trees away from my yard

An external benefit, also known as a positive externality, occurs when a third party gains a benefit from an activity that they were not directly involved in. In this case, the neighbor keeping the leaves from his trees away from your yard is an example of an external benefit because it reduces your workload and keeps your yard cleaner without any direct effort from you.