Which duty of a US representative is the expense report an example of?

The correct answer is C. Hiring and managing a staff.

An expense report is typically related to how representatives manage their office budgets and staff expenditures, as it accounts for costs incurred while fulfilling their duties. This process falls under the broader responsibility of hiring and managing their staff and ensuring that budgetary guidelines are followed. If you have more questions or need further assistance, feel free to ask!