Which of the Following Statements Is NOT True About Post-Campaign

Which of the following statements is NOT true about post-campaign evaluation?

A) Marketers spend little time studying advertising effectiveness because there are so many variables that shape the effectiveness of an ad.
B) Testing ad effectiveness can be done either before or after the campaign.
C) Most advertising campaigns aim to create an image for the product instead of asking for action, so their real effect is unknown.
D) Even if an ad campaign has been particularly successful, advertisers will typically conduct a post-campaign evaluation.
E) Evaluating an advertising campaign can be the most demanding task facing advertisers.