Which of the Following Statements About Sales Tests Is Most

Which of the following statements about sales tests is most accurate?

A) With sales tests, product information, product samples, or premiums are offered to an ad's readers or viewers, and ads generating the cost inquiries are considered the most effective.
B) With sales tests, a question such as, "What ads do you remember seeing yesterday?" is asked of respondents without any other prompting.
C) Sales tests involve studies such as controlled experiments and consumer purchase tests to measure actual purchases.
D) In a sales test, respondents are asked questions to measure changes in their attitudes after an advertising campaign.
E) In a sales test, respondents are first shown an ad and then asked whether their previous exposure to it was through reading, viewing, or listening.