Final answer:
The Billing department is in charge of directing charges to the correct payer during the adjudication of research participant's bills, ensuring accurate financial management for study-related expenses.
Step-by-step explanation:
Adjudication of research participant's bills allows the Billing department to direct charges to the correct payer. When research participants are involved in a study, the financial aspects related to their participation, such as compensations and medical expenses, need to be managed accurately. The Billing department is responsible for ensuring that these charges are directed to the appropriate payer, which may include insurance companies, study sponsors, or the participants themselves if necessary.