I am going to assume from the heading that it is one single scope that can not be replaced so has to be near faultless on a firearm that will do it's work from ten yards to 400 yards in a pinch, with the majority being of a hunting subsistence tenor.
I would choose a straight 4x in a longish tube and of at least Leupold quality, in point of fact an old 4x Leupold would suffice quite nicely.
