单项选择题

By saying "It will represent a 'watershed moment' in the evolution of the internet as an advertising medium", the trade magazine suggests

A.Google and Yahoo! share advertising revenues with television networks.
B.The success of Google and Yahoo lakes a turning-point to online advertising.
C.America's three big television networks play an important role in the development of advertising medium.
D.Google and Yahoo! build up their status in advertising.