How does vSphere High Availability calculate the memory slot size of a virtual machine?

A.
Virtual machine memory reservation + overhead of largest virtual machine

B.
Virtual machine memory reservation – overhead of largest virtual machine

C.
Virtual machine memory reservation + overhead of smallest virtual machine

D.
Virtual machine memory reservation – overhead of smallest virtual machine

Explanation:

Reference: http://www.yellow-bricks.com/2009/08/12/ha-and-slot-sizes/