Company A Inc. purchases $4,562,500 in goods per year from its sole supplier on terms of 2/15, net 50. If the firm chooses to pay on time but does not take the discount, what is the effective cost of its trade credit? (Assume a 365-day year.)

a. 24.63%

b. 21.28%

c. 23.45%

d. 20.11%

e. 21.17%