You have configured a workstation to boot in runlevel 4, but you now find that the X server will not
start correctly and the machine will not allow local access. What would be the most effective
command to run at the LILO prompt to regain local access to the machine, when the last known
working kernel image was linux?

Answer: linux s

Explanation:
see http://www.snow.nl/dist/xhtmlc/ch02s02.html
To boot into single user mode in LILO type the name of the label corresponding to the kernel you’d
like started followed by an “s”, “S” or the word “single”. If the label is “Linux”, you can type one of
the following after the
LILO prompt:
LILO: Linux s
LILO: Linux S
LILO: Linux single
If you have defined a runlevel, let’s say runlevel 4, which is a text-only runlevel, you can type the
following line to boot into runlevel 4 and regain access to your system:
LILO: Linux 4