Ralph Walters wanted to begin an exercise program and decided to enroll in a local aerobics class. He was told that he would need proper aerobic work-out shoes. Ralph went to an athletic shoe store and explained his needs to the sales clerk and also added that since he had never done aerobics, he was unsure what type of shoe he would need. The sales clerk recommended a shoe that Ralph purchased. When Ralph arrived at aerobics class, his instructor said his shoes were not appropriate for aerobics and that Ralph might injure himself if he used them for the workout. When Ralph returned to the store with the shoes, the store refused to exchange them, citing the three-day limitation on returns. Suppose Ralph's sales receipt had stamped on it in red letters "AS IS." The shoe store: a. has breached the implied warranty of fitness for a particular purpose and is required to refund Ralph's money or exchange the shoes. b. is within its rights to refuse to take the shoes back. c. has not breached any warranty since Ralph had no contract with any promises written in it. d. none of the above