The regular price per can of a certain brand of soda is $0.40. If the regular price per can is discounted 15 percent when the soda is purchased in 24-can cases, what is the price of 100 cans of this brand of soda purchased in 24-can cases? Options:
A) $ 16.32  B) $ 18.00  C) $ 21.60  D) $ 34  E) $ 28.80

Rationale: "the discounted price of one can of soda is ( 0.85 ) ( $ 0.40 ) , or $ 0.34 . therefore , the price of 72 cans of soda at the discounted price would be ( 100 ) ( $ 0.34 ) = 34 answer : d ."
Answer: D