Which of the Following Best Explains Why the Amount of Prescription

Which of the following best explains why the amount of prescription drug advertising has increased since 1997?

A) The American Medical Association approved the use of advertising to promote prescription drugs.
B) The federal government loosened its controls on the production of prescription drugs.
C) Pharmaceutical companies realized that a pull strategy would be more effective than a push strategy.
D) The federal government loosened its controls on pharmaceutical advertising.
E) Patents held by many pharmaceutical companies expired,resulting in price competition and heavy advertising.