When memory is reclaimed from a virtual machine using vmmemctl, what is the maximum amount that can be reclaimed by default?

A.
50% of the unreserved memory

B.
65% of the available memory

C.
65% of the unreserved memory

D.
50% of the available memory

Explanation:
Memory Provisioning Recommendations for VMware Infrastructure 3 Operational Best Practices, page 11.
Memory Balloon – This counter reflects the total amount of memory the VMkernel is effectively "borrowing" from virtual machines via the VMTools balloon driver running inside the guest OS. Balloon driver activity indicates over-commitment of ESX host memory. By default, the VMkernel may balloon up to 65% of a virtual machine’s configure RAM.