In the Cisco Catalyst 6500-E Series chassis, what are three key chassis specifications? (Choose three.)

A.
requires Cisco IOS 12.2(1)SXD and beyond

B.
three-slot chassis supports CEF720 line cards

C.
is backward-compatible with all existing software versions

D.
six- and nine-slot chassis support only 6000-W power supplies

E.
supports all existing supervisors, line cards, switch fabrics, and software releases