On the other hand, if I picked 2, I'm promoting free speech and the right to knowledge, but this is essentially suicide. There'd be no chance of survival and I'd probably be hated for killing us all, and then I'd be killed. But I save the lives of the offspring of any survivors (if there are any, and the aliens don't return).
So, if the aliens don't return, and there are at least say, 10 survivors, I'd pick 2. Because I'd know I'd save countless lives in my sacrifice. But if there are no survivors, and the aliens stay, then since we're doomed either way we might as well pick 1 and let us live for 1000 more years.