请帮助解答，谢谢！

bjhotsky

8. A network diagnostic tool that monitors and records network information is a(n):\r\n\r\n    A. online monitor.\r\n    B. downtime report.\r\n    C. help desk report.\r\n    D. protocol analyzer.\r\n\r\n        Protocol analyzers are network diagnostic tools that monitor and record network information from packets traveling in the link to which the analyzer is attached. Online monitors (choice A) measure telecommunications transmissions and determine whether transmissions were accurate and complete. Downtime reports (choice B) track the availability of telecommunication lines and circuits. Help desk reports (choice C) are prepared by the help desk, which is staffed or supported by IS technical support personnel trained to handle problems occurring during the course of IS operations. \r\n\r\n题库里面答案是B,解释里面好像D,到底哪一个？

cisamaqing

指的是Sniffer这样的工具

bjhotsky

谢谢！我觉得也应该是d