The correct answer is: A. /boot/lilo.conf
/boot/lilo.conf is a configuration file used by the LILO boot loader. It contains information about the kernel images that LILO can boot, as well as the location of the boot sector. To boot a new kernel image, you need to edit /boot/lilo.conf and add a line for the new image.
The following is an example of a line in /boot/lilo.conf:
image=/boot/vmlinuz-2.6.32-244.2.1.el6.x86_64
label=linux
initrd=/boot/initrd-2.6.32-244.2.1.el6.x86_64
This line tells LILO to boot the kernel image located at /boot/vmlinuz-2.6.32-244.2.1.el6.x86_64. The label “linux” is used to identify this kernel image. The initrd image is also specified, which is necessary for some kernels.
Once you have edited /boot/lilo.conf, you need to run the lilo command to update the boot sector. This will make the new kernel image available for booting.
The other options are incorrect because they are not configuration files used by the LILO boot loader.