Which of the Following Statements About the Role of Ad

Which of the following statements about the role of ad agency media departments is true?

A) Many large advertisers use media departments in a variety of different agencies to purchase media time and space.
B) A media department's ability to negotiate prices and make effective use of the vast array of media options has become very important.
C) The media department of an ad agency reviews information on demographics,magazine and newspaper readership,radio listenership,and consumers' television viewing habits.
D) Many large advertisers are consolidating their media buying with one or a few agencies' media departments to save money and improve media efficiency.
E) All of the above statements about the role of ad agency media departments are true.