From this menu:
Default Source
You can:
Set a default paper source for all print jobs.
Tray <x>*
MP Feeder
Manual Paper
Manual Env
NOTE: The items on the default source vary depending on the device type and the attachments and/or supplies installed on it. Size and Type settings are configured for each of the listed Default Source options under Tray Configuration.
Configure MP
Determine when the printer selects paper from the multipurpose feeder and the mode of operation of the multipurpose feeder.