Fair bit of confusion here. Even Boeing Obi Wan Kenobi BOAC felt he had to say something (nice to see you on an Airbus thread - yes I have gone to the dark side...).
Just to clarify it for toby 320:
1) LAND/FLARE/ROLLOUT will be displayed as long as you have selected an ILS approach and have ONE autopilot engaged
2) As long as the above is displayed the aircraft will autoland, REGARDLESS of whether you selected a DH or DA/MDA but you MUST have at least Cat II displayed on the FMA (based on systems availability)
3) Auto callouts will be armed regardless of selecting DH or DA/MDA. They will just be based on either baro alt or rad alt depending on which one you picked. There are additional callout modifications specific to each type of approach e.g. ONE HUNDRED as opposed to HUNDRED ABOVE if you picked NO DH (Cat IIIb).
So to go back to your original question, you can select a Cat I minimum in the MDA field of the MCDU and do an Autoland. Airbus recommends you select both autopilots if they are available. But it will work with one as long as no failures occur to downgrade the landing capability below Cat II (again, as displayed on FMA).
Beware of the ILS-sensitive area being not protected (see BOAC post)
P
Edit: both Wizaird and aristoclis were faster than me
