Questions 22 ～ 25 are based on the following dialogue concerning "digital divide". What is the main idea of the dialogue

A．Income is the main factor that determines who are online and who are not.
B．The digital divide is determined by factors such as income, race and age.
C．More and more people in the United States will go online in the near future.
D．Both men and women are interested in going online but they visit different sites.