Which of the Following Statements About Comparative Advertising Is True

Which of the following statements about comparative advertising is true?

A) Comparative advertisements now constitute over 90% of all television ads.
B) Comparative advertisements attract less consumer attention in the advertiser's brand.
C) Comparative advertisements need market research to provide legal support for their claims.
D) Comparative advertisements have been banned by the Federal Trade Commission.
E) Comparative advertisements can, and often, do more harm than good.