Hear! Hear! to all who are voting for the third option.
BTW, there was one other thing I thought they were overlooking. If they wait for possible invulerability to occur it would be possible that the condition might never fix itself. While the acid wouldn't burn in the same way it would mean that at some point surgery isn't an option. So if there is only a partial invulnerability (my eyes cross at what that looks like, since obviously partial invulnerability would be vulnerable) he could end up with the worst of both worlds.
Elisabeth
