From Codex: Eldar p.51:
Eldrad Ulthran, Staff of Ulthamar -- 'In combat it always wounds on 2+ and ignores armour saves'
So is the Staff of Ulthamar
a) An unusual power weapon (i.e. AP3, User Str)
b) AP2 for ignoring every possible armour save value
c) AP- but just ignoring armour saves
d) Something else?
Please state your reasoning as well.