In Lee Benham's 1972 Article Examining the Impact of Advertising

In Lee Benham's 1972 article examining the impact of advertising on the average price paid for a pair of eyeglasses, Benham found that

A) the average price paid for eyeglasses was nearly 20% higher in the states that did not restrict advertising.
B) the average price paid for eyeglasses was nearly 20% lower in the states that did not restrict advertising.
C) there was no difference in the average price paid between states that restricted advertising and those that did not.
D) the average price paid for eyeglasses was almost 5 times higher in the states that did not restrict advertising.