You plan to take a 15-year mortgage in the amount of $500,000 to buy a home. The bank charges 4% annual interest compounded monthly. You are going to pay off this loan by fixed installments (fixed total payment) to be made at the end of each month for fifteen years. How much is each installment payment?

a. $3,123.47

b. $4,542.31

c. $4,223.72

d. $3,698.44