Final answer:
An internal customer is a coworker who relies on the work and services provided by their colleagues.
Step-by-step explanation:
The correct answer is c. Coworker. An internal customer refers to anyone within a company who relies on the products or services provided by another department or individual within the same company. In this case, a coworker is an example of an internal customer because they rely on the work and services provided by their colleagues to complete their own tasks effectively.