Which two vSphere components can be upgraded by Update Manager? (Choose two.)

A.
vSphere Management Assistant (vMA)

B.
Virtual machine hardware

C.
VMFS file system

D.
VMware Tools

Explanation:
http://pubs.vmware.com/vsphere-4-esx-vcenter/index.jsp?topic=/com.vmware.vsphere.upgrade.doc_41/esx_upgrade/intro_host/r_list_of_ upgraded_components.html