An administrator wants to monitor virtual machines on a host and send notifications when memory usage reaches 80%.
What should the administrator create in vCenter Server to accomplish this?

A.
A host alarm that will monitor virtual machine memory usage and set a trigger to email the notification.

B.
A vCenter Server alarm that will monitor virtual machine memory usage and set an action to email the notification.

C.
A host alarm that will monitor virtual machine memory usage and set an action to email the notification.

D.
A vCenter Server alarm that will monitor virtual machine memory usage and set a trigger to email the notification.