How does HP defines a balanced virtual machine system architecture?

A.
Industry recommended best practice combination of 3.5 GB of memory and 400MG of I/O per
virtual machine

B.
A redundant combination of extended memory, I/O, storage, and virtual machines in each
enclosure

C.
The combination of computer power, I/O and storage that yields the best return on investment

Explanation:
http://h30507.www3.hp.com/t5/Eye-on-Blades-Blog-Trends-in/Keys-To-Extend-VirtualInfrastructure-with-HP-BladeSystem-and-HP/ba-p/95351(balanced architecture, first sentence)