After the solution, how does the middle group make two eyes?
Black ends in gote, so white begins by attacking, and I think this is Black's best response. After , Black must make an eye with at a, and b & c are maiai for the second eye. This is ko for life, though, since, if black fills the ko first, white can play a, reducing the group to one eye.
Is that the best black can do?
fractic: With black lives unconditonally with eyes at the circled points.