I will have to say 4. If anything.. we're the aliens, here.. on Earth. Which is why everything is so mysterious... Take this example.. I'll compare our race being born here on Earth, to a baby being born in a hospital room.. See, our race supposedly born here on Earth, with millions of years of evolution and all of this, yet we have not explored all of the Oceans? we haven't explored everything? Now a baby being born in a hospital room, does that baby stay in that one room its whole life? No, it grows up and explores, it would know the rest of the hospital, even a town. So why don't we know our home inside and out? Get what i'm saying? If our species is -from- here, and Earth is our hospital, why is the rest of the hospital so mysterious and unexplored? The only answer to that, that I can come up with... personally.. is that this is not our hospital.