You have installed a new window manager on an Ubuntu system, and find that it is not listed in the "Session" menu on the graphical login screen. Which of the options below will fix this?

A.
Create a file called ~/.Xsession and add a line which starts the window manager.

B.
Add a suitable line to /etc/gdm/Xsession which starts the window manager.

C.
Add an exec statement to /etc/X11/xinit/xinitrc which starts the window manager.

D.
Create a .desktop file and place it in /usr/share/xsessions.