I aspire to the first option, but practice the fourth. I don't take the shot unless I'm sure it will be a one-shot kill. But part of follow-through for me is to get that second round chambered ... unless, of course, I'm bow hunting.
Thus far, all my kills with a firearm have been one-shot drops. I say "drops" rather than "kills" because I did put a finisher into a buck I spined. He was dead but didn't know it yet, so I had to convince him. But let's not talk about the one-shot misses, okay?