Which BladeSystem server has four sockets and up to seven available expansion mezzanine slots?

A.
BL280c G6

B.
BL460c G7

C.
BL680c G7

D.
BL860c i2

Explanation:

Reference:
http://h20195.www2.hp.com/V2/GetPDF.aspx/4AA3-4212ENW.pdf