Which of the following situations will result in VMware HA restarting virtual machines?

Which of the following situations will result in VMware HA restarting virtual machines? (Choose Two.)

A.
A guest OS is manually powered off.

B.
A guest OS fails.

C.
An ESX Server in the cluster is put into Maintenance mode.

D.
An ESX Server in the cluster becomes isolated from the network.

Explanation:
VMware vSphere – VMware High Availability

1. Monitors virtual machines to detect operating system and hardware failures.
2. Restarts virtual machines on other physical servers in the resource pool without manual intervention when server failure is detected.
3. Protects applications from operating system failures by automatically restarting virtual machines when an operating system failure is detected [B above]

vSphere Availability Guide ESX 4.0 ESXi 4.0 vCenter Server 4.0, page 22 and 23.

Host isolation response determines what happens when a host in a VMware HA cluster loses its service console networks (or VMkernel networks, in ESXi) connection but continues running. Host isolation responses require that Host Monitoring Status is enabled. When this occurs, the host executes its isolation response. The responses are:
Leave VM powered on, Power off VM, and Shut down VM.

VM Monitoring restarts individual virtual machines if their VMware Tools heartbeats are not received within a set time. You can configure the degree to which VMware HA is sensitive to such non-responsiveness. If you select Enable VM Monitoring, the VM Monitoring service (using VMware Tools) evaluates whether each virtual machine in the cluster is running by checking for regular heartbeats from the VMware Tools process running inside the guest. If no heartbeats are received, this is most likely because the guest operating system has failed or VMware Tools is not being allocated any time to complete tasks. In such a case, the VM Monitoring service determines that the virtual machine has failed and the virtual machine is rebooted to restore service.

Therefore, if an ESX Server in the cluster becomes isolated from the network, it can be configured to shut down a virtual machine, which can then result in VM Monitoring restarting the individual virtual machine, [D above].