The rate of discount, R, can be determined using the formula, where P is the regular price of an item and D is the discount or amount saved off the regular price. Find the rate of discount on a sweater with a regular price of $39 that is on sale for $27. If necessary, round to the nearest hundredth.
A. 1.69
B. 0.31
C. 0.69
D. 1.31