In order to use the option dom0_mem to limit the amount of memory assigned to the Xen Domain-0, where must this option be specified?

A.
In its Makefile, when Xen is built.

B.
In the configuration file /etc/xen/Domain-0.cfg, when Xen starts.

C.
In the bootloader configuration, when Xen is booted.

D.
In its .config file, when the Domain-0 kernel is built.

E.
In any of Xen’s global configuration files.