After upgrading the vSphere infrastructure and VMware Tools to version 6.5, the "Upgrade VM Compatibility" option is grayed out in the vSphere Web Client. (See Exhibit.)
What must the administrator do to enable the VM compatibility upgrade?
A. VMware Tools should be upgraded last.
B. Restart the ESXi server.
C. Uninstall VMware Tools.
D. Power off the virtual machine.
Correct answer is D
https://pubs.vmware.com/vsphere-51/index.jsp?topic=%2Fcom.vmware.vsphere.upgrade.doc%2FGUID-60768C2F-72E1-42E0-8A17-CA76849F2950.html
After upgrade….. so its B.
D
https://docs.vmware.com/en/VMware-vSphere/6.5/com.vmware.vsphere.vm_admin.doc/GUID-41AA8386-D1DA-4788-9718-216C62CE112A.html
After upgrading the vSphere infrastructure you restarted ESXi as a requirement.
vmware tool upgrade NO require downtime to restart , differently Upgrade Virtual Machine Compatibility need downtime to shut down and power on the virtual machine.
The answer is D. The link Steve provided clearly says that VMware tools must be upgraded before compatibility level. Not last.
should be A. Poweroff is optional. VMware tools upgrade is prerequisite
https://docs.vmware.com/en/VMware-vSphere/6.5/com.vmware.vsphere.vm_admin.doc/GUID-60768C2F-72E1-42E0-8A17-CA76849F2950.html
Power off is optional for some Linux OS, not every OS
Would also say, answer is D
https://docs.vmware.com/en/VMware-vSphere/6.5/com.vmware.vsphere.vm_admin.doc/GUID-60768C2F-72E1-42E0-8A17-CA76849F2950.html
D
https://docs.vmware.com/en/VMware-vSphere/6.5/com.vmware.vsphere.vm_admin.doc/GUID-41AA8386-D1DA-4788-9718-216C62CE112A.html
During the virtual machine compatibility upgrade, you must shut down the virtual machine for all guest operating systems.