A workstation no longer has network connectivity. Upon visual inspection, all connectors andsettings seem to be properly configured. Which of the following tools should the technician use to troubleshoot this issue? （）

A. Power supply tester
B. Cable tester
C. Loopback plugs
D. Multimeter
E. Butt set

A. Roll back the driver.
B. Install the original video card and reboot.
C. Delete the monitor.
D. Remove the video card and reboot.

A.C：\Windows\System32（x64）
B.C：\Windows\System
C.C：\Windows\System32
D.C：\Windows（x64）\System32