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.