First off I rarely ever play this game.I am almost positive the answer is fold though.Reason being you hold your outs in your hand since you can only use 2 of your hole cards.I'm pretty sure when playing omaha you have to have a very strong hand in order to win a showdown.What strong hands can you possibly get with quads?You can't get a set,flush,or straight.The best you can hope for is a full house if 3 like cards come on the flop,which is not likely.
Now that I've typed this I have convinced myself that folding is the only option.Anyone else with more experience in this game will probably tell you the same if they chime in.If not then I was wrong and it wouldn't be the first time.
Fold always -- even if you have trips in the hole. These are horrible hands. Only exception I occassionally make is something like AAAK with suited ace or KKKQ/KKKA with suited king.
fold fold fold, unelss your on the big blind and you check with quad aces, the flop comes 2,2,2 it is checked around, then turn is a 2. Then you can feel confident since you would be holding the nuts with two's full of aces