What is the most likely explanation?

Immediately after installing ESXi, an administrator observes that the Configure Lockdown Mode
option is grayed out in the Direct Console User Interface (DCUI).
What is the most likely explanation?

A.
The host has not yet been added to a vCenter Server.

B.
The BIOS on the host does not have NX/XD enabled.

C.
The ESXi host is running in evaluation mode.

D.
The host requires a reboot before this feature is available.