Read the passage carefully and choose the correct answer

Although computers are considered the most perfect and effective devices in our modern time, we cannot avoid some certain problems when we are working on a computer. Letters and phone conversations are private. It is against the law to open someone’s mail without permission or to listen secretly to someone's telephone conversation. And now there are laws to protect the privacy of e-mail. It is also against the law to read the messages that a person sends or receives on a computer. Although each person has a secret password for his or her e-mail, sometimes the passwords are discovered by hackers and the mail box is opened. 

Recently several companies that do business on the Internet have been attacked. The attackers sent huge amounts of useless e-mails to the Web sites of these companies. The effect was to slow or stop the ability of the companies to do their business. Such actions are known as “denial of service” attacks. The companies say they may have lost millions of dollars because they were not able to provide goods and services during the attacks. Most of the companies were able to solve the problem in about three hours. The victims of the attacks included some of largest and most successful companies on the Internet, such as Yahoo, Amazon, and Com and E-Trade. The police have investigated the attackers. The computer industry leaders have discussed the electronic attacks and the problems of computer crime. They suggest that a person who is found guilty of such a crime should be sentenced to at least 10 years in prison.

It is _____ to read the messages that a, person, send or receive on a computer.

• A. 
  legal
• B. 
  illegal
• C. 
  encouraged
• D. 
  advisable