which circumstance will a virtual machine always fail to power on?

Under which circumstance will a virtual machine always fail to power on?

A.
when there is no free space in VMFS

B.
when the virtual machine’s reservation cannot be guaranteed

C.
when the host’s license server became inaccessible 24 hours ago

D.
when the virtual machine’s memory is configured at greater than 3.6 GB

Explanation:
Resource Management Guide : Resource Management Jumpstart : Understanding Virtual Machine Resource Allocation : Virtual Machine Attributes: Shares, Reservation, and Limit

Reservation specifies the guaranteed reservation for a virtual machine. The server allows you to power on a virtual machine only if the CPU and memory reservation is available