Which three VMware-recommended best practices should an administrator follow before upgrading to vSphere 6.5? (Choose three.)

Which three VMware-recommended best practices should an administrator follow before upgrading to vSphere 6.5? (Choose three.)
A . Disconnect ESXi host from vCenter.
B . VMware Tools are installed in the virtual machine.
C . Ensure that the system hardware complies with ESXi requirements.
D . Back up the host.
E . Check the interoperability of any other software integrated with vSphere.

Answer: C,D,E