单项选择题
A. The theoretical maximum cable length
B. The theoretical maximum bandwidth
C. The theoretical port limit of the cable
D. The quality level of the copper wiring used
单项选择题 Which of the following wireless technologies can operate at only 5GHz?（）
单项选择题 An administrator has added a new access point to the network to provide additional coverage. A heat-map survey shows coverage now extends beyond company property and is interfering with other wireless networks in the area. How should the administrator modify the new installation to stop the interference?（）
单项选择题 Which of the following layers of the OSI model is the presentation layer?（）