Answer:
D. social loafing.
Step-by-step explanation:
Social loafing: In psychology, the term "social loafing" was proposed by Max Ringelman during the 1890s, and is described as a phenomenon in which an individual tends to exert less attempt or effort on a particular task if he or she is being involved in a group instead when he or she works alone. However, working with a specific group might improve the performance of a person by pooling the skills involved.
In the question above, Courtney's behavior can be attributed to social loafing.