Antonio plc takes 60 days to pay for goods purchased from its main supplier. To encourage more prompt payment the supplier has offered the company a 3 per cent discount if payment is made within 10 days. However, Antonio plc has refused to accept the offer. What is the approximate annual cost of the discount foregone?

a. 21.9%

b. 18.2%

c. 18.0%

d. 0.4%