Melissa engages in an activity that influences the well-being of a bystander. In order for Melissa's activity to give rise to an externality, it must be the case that
A. the well-being of the bystander is adversely impacted by Melissa's activity.
B. Melissa neither pays nor receives any compensation for her activity.
C. Melissa fails to recognize the impact of her activity on the bystander's well-being.
D. the bystander fails to recognize the impact of Melissa's activity on his or her well-being.