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 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 with a vmxnet network adapter.

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

Explanation:
Page 142 from vsphere-esxi-vcenter-server-50-upgrade-guide.pdf