The Pay Scale at a Warehouse Is $15 Per Hour

The pay scale at a warehouse is $15 per hour for a basic eight-hour day, and $20 per hour for overtime of up to four hours, and $25 for overtime exceeding four hours a day. Angela works 10 hours a day. What are her marginal and average pay?

A) Marginal pay = $20 per hour, average pay = $16 per hour.
B) Marginal pay = $15 per hour, average pay = $20 per hour.
C) Marginal pay = $15 per hour, average pay = $15 per hour.
D) Marginal pay = $15 per hour, average pay = $17.30 per hour.