The Parent-Teacher Association (PTA)wants to find out how much students pay for school supplies at the beginning of the school year, so it conducts a survey at certain local stores. PTA members visit these stores to find the prices of the items on the students' supply lists. What is the sample in this study? A. The prices of listed items at the selected stores
B. The prices of pencils at the selected stores
C. The prices of listed items at all local stores
D. The prices of listed items at one store