登录之后可查看解析

Answer (D) is correct . Viruses are a form of computer sabotage. They are programs hidden within other programs that have the capacity to duplicate themselves and infect other systems. Sharing of storage media or participation in computer networks creates exposure to viruses. Viruses may result in actions ranging from harmless pranks to erasure of files and programs. A back door is a shortcut created in an operating system that permits a programmer simple access to the system.

Answer (A) is incorrect because The programmer would most likely be denied access to the center.
Answer (B) is incorrect because The programmer would not know the necessary passwords.
Answer (C) is incorrect because Collusion is less likely than individual wrongdoing.