What is a key benefit of the HP Z200 Workstation over its predecessor, the HP
xw4600?

A.
3D graphics

B.
Energy Star 5.0

C.
Gigabit LAN

D.
USB 2.0

Explanation:
http://h10010.www1.hp.com/wwpc/pscmisc/vac/us/product_pdfs/Z200_datasheet_011309_highres.pdf (first page, second column, 4thbulleted point. HP xw4600 has Energy start 4.0)