In the eighties, the Americans as a whole ______.

A．advertising is no different from person -to- person selling in substance
B．advertising extends sales promotion to a larger area
C．advertising has greatly improved the production of goods
D．it is very expansive to advertise a new product

A．advertisement often persuades people to buy what they don' t really want
B．advertisement can never really influence people's ability to decide
C．whether to buy an advertised product is up to the would - be customer
D．the effect of an advertisement on the public is difficult to determine