Question: NAME_1 buys p pounds of bananas for 40 cents per pound. She pays the clerk with a twenty-dollar bill. The clerk subtracts the total cost of the bananas from the twenty-dollar bill to determine the amount of change to give NAME_1. Which expression represents the amount of change NAME_1 should receive?
A: p - 20
B: 20 - 40p
C: 20 - 0.40p
D: 0.40p - 20
Please eliminate two incorrect options first, then think it step by step and choose the most proper one option.