Stacking boosts with Belkar's Leaping Attack?
Let's say Belkar has 3 copies of Leaping Attack in play, and 1 of Twin Daggers of Doom. Each copy of Leaping Attack gives Twin Daggers of Doom +1 attack and +1 range. Each time Leaping Attack is boosted, it's another +1 attack and +1 range. So with 3 copies of Leaping Attack and 1 of Twin Daggers of Doom, is it:
a) Each copy of Leaping Attack is boosted by the other two, and boosts them in return; so each copy is worth +3 attack and +3 range, and the 3 combined make it +9 attack and +9 range (and then the base +3 from normal Twin Daggers of Doom added on top of that)?
b) Like with the new Monster Support Rule, each copy of the schtick only boosts one other copy, the topmost eligible one. The top one boosts the middle one, the middle and bottom ones boost the top one; in total, there is one twice-boosted card, one once-boosted card, and one un-boosted card. 3 + 2 + 1 = a total of +6 attack and +6 range?
Whichever one it is, why? Can only one be used at a time, or is a limit on boosting, or is it no limit and he can get up to a constant +12 attack and +12 range?