The /etc/X11/xdm/xdm-config file is the default configuration file of XDM. The X Window Display
Manager (XDM) is the default display manager for the X Window System. XDM is distributed as part of XFree86 and is configured by a series of files located in /etc/X11/XDM. Some of the important files of XDM are given below in the list:
Xaccess: It is used to control inbound requests from remote hosts.
Xresources: This file holds configuration information for XDM resources and the graphical login screen. It can be edited to modify the appearance of the XDM login screen. Xservers: This file is used to associate the X display names with either the local X server software or a foreign display such as an X terminal.
Xsession: This file contains the script XDM launches after a successful login.
Xsetup_0: This file defines how XDM will open. It is a script started before the graphical login screen.
It often includes commands to set colors, display graphics, or run other programs. This script is executed as root.
XDM-config: This file is used to configure XDM configuration resources.
Answer option B is incorrect. $HOME/.Xauthority is the user authorization file where XDM stores keys for clients to read.
Answer option D is incorrect. The /usr/bin/xterm file is the default session program of XDM.
Answer option C is incorrect. It is not a valid XDM configuration file.
