Which two events will result in a vSphere 5.x host running a virtual machine that contains an older virtual hardware version?

Which two events will result in a vSphere 5.x host running a virtual machine that contains an older virtual hardware version? (Choose two.)

A.
A virtual machine is created on a vSphere 5.x host and virtual disks for the VM are created on a VMFS3 datastore.

B.
A virtual machine was migrated from a vSphere 4.x host.

C.
A virtual machine is created on a vSphere 5.x host with a vmxnet3 network adapter.

D.
A virtual machine is created on a vSphere 5.x host and is attached to an existing virtual disk created with vSphere 4.x.