Personally, I don't believe any government has the competence to run this sort of cover up campaign without something coming out in the way of evidence. I am comforted by the general incompetence of large organisations. Because of this, I'll go with option A.far-trader said:B - Aliens are real, the government is (choose 1: in cahoots; controlled by; replaced with) them and they deny, deny, deny. It's a big cover-up where everything is weather balloons, mass delusion, clouds, ball lightning, top secret aircraft, etc. etc.