vCenter Server Appliance Resource Monitoring

A.

The tool used to monitor vCenter Server Appliance resources is "vimtop" (Answer A).

Vimtop is a command-line utility that is included with the vCenter Server Appliance. It provides real-time performance data for the vCenter Server Appliance, including CPU usage, memory usage, and network activity. Vimtop can be used to monitor the overall health of the vCenter Server Appliance and identify performance issues.

Esxtop (Answer B) is another command-line utility used for monitoring performance on ESXi hosts. It provides real-time information about CPU usage, memory usage, disk usage, and network activity on the host level.

Esxcli (Answer C) is a command-line interface used to manage and troubleshoot VMware ESXi hosts. It allows administrators to perform a wide range of management tasks, such as configuring network settings, managing storage, and updating firmware.

Vmstat (Answer D) is a command-line utility used to monitor system performance on Linux and UNIX systems. It provides information about CPU usage, memory usage, and disk activity.

Therefore, Vimtop is the best option to monitor the vCenter Server Appliance resources, as it is specifically designed for this purpose and provides the most relevant real-time data.