On a purchase of $127, a store offered a payment plan consisting of a $27 down payment and 12 monthly payments of $10 each. What percent of the purchase price, to the nearest tenth of a percent, did the customer pay in interest by using this plan?	Choose the correct choice from the following options:
A) 18.3 %
B) 15.3 %
C) 21.3 %
D) 22.3 %
E) 25.3 %

Rationale: "12 * 10 + 27 = 147 ( 27 / 127 ) * 100 = 21.3 answer : c"
Answer: C