What is the main idea of the passage？A．Old people are in great need of improving their com

What is the main idea of the passage？

A．Old people are in great need of improving their computer skills.

B．The gap between those who use Internet and those who don"t is widening.

C．Hackers and privacy problems hinder the development of Internet.

D．The young should help the old grasp the use of Internet.

请帮忙给出正确答案和分析，谢谢！