Overtime occurs when an employee works more than:

The correct answer is C. 40 hours a week.

Explanation: Overtime is typically defined as the hours worked beyond the standard 40 hours in a week for most non-exempt employees according to the Fair Labor Standards Act (FLSA) in the United States. When an employee exceeds this 40-hour threshold, they are generally entitled to receive overtime pay, which is usually calculated at one and a half times their regular hourly rate.