单项选择题
A buyer failed to take advantage of the vendor's credit terms of 2/15, n/45, but instead paid the invoice in full at the end of 60 days. By not taking advantage of the cash discount, the buyer lost the equivalent of ____________ annual interest on the amount of the purchase.
A、 12.2%
B、16.2%
C、 18.9%
D、24.3%
E、24.5%