Which of the Following Is One of the Nine Principles

Which of the following is one of the nine principles of Positioning Advertising Copy Testing (PACT) ?

A) Require agreement about how the results will be used in advance of each specific test.
B) Adhere to the consideration that an advertising stimulus should be exposed only once.
C) Provide controls to increase the biasing effects of an exposure context.
D) Use a convenience sample.
E) Provide a single unique measurement to adequately assess an ad's performancE.One of the nine principles of good copy testing is to require agreement about how the results will be used in advance of each specific test.