This is one of the problems that I won't solve in actual play even if it is not so difficult when posed as a problem. Thanks to hhw for pointing out a mistake.
(;AB[qb]AB[pb]AB[qc]AB[qd]AB[rd]AB[pd]AB[od]AB[nd]AB[md]AB[lc]AW[lb]AW[oc]AW[nc]AW[pc]AW[ob]AB[mc]AW[mb]AW[kc]AW[kd]AW[me]AW[le]AW[ne]AW[oe]AW[pe]AW[qe]AW[re]AW[qh]AW[pa]C[Black to survive.]AP[goproblems]
(;B[na]
(;W[nb]
(;B[sb];W[ra]
(;B[rb];W[qa]
(;B[oa];W[ma]
(;B[oa];W[na]
(;B[sa]
(;W[jb];B[oa]C[CHOICERIGHT])
(;W[sd]
(;B[sc];W[jb];B[oa]C[CHOICERIGHT])
(;B[kb];W[jb]
(;B[sc]C[CHOICERIGHT])
(;B[oa]C[CHOICERIGHT]))
(;B[oa];W[pa]
(;B[qa];W[sc])
(;B[sc];W[qa]))))
(;B[kb];W[jb]
(;B[ka];W[ja];B[sa];W[la];B[oa]C[RIGHT])
(;B[sa];W[ka];B[oa]C[This is correct but gives white more eye shape than the best solution.RIGHT])))
(;B[sa];W[oa])
(;B[kb]C[NOTTHIS]))
(;B[sa];W[oa])
(;B[kb]C[NOTTHIS]))
(;B[qa];W[sd])
(;B[kb]C[NOTTHIS]))
(;B[qa];W[sd]C[Black is dead.])
(;B[sd];W[qa]
(;B[sb];W[ra])
(;B[ra];W[sb]))
(;B[rb];W[sc];B[sd];W[sb]
(;B[sa];W[qa])
(;B[qa];W[sa]C[This is bent four in the corner (Black is dead under japanese rules and nearly dead under other rule sets).])))
(;W[oa];B[qa];W[nb];B[sb]C[This is not the hardest resistance.RIGHT]))
(;B[sb]C[];W[ra]
(;B[na]
(;W[nb]
(;B[qa];W[sd])
(;B[oa];W[sd];B[sc];W[rb])
(;B[rb];W[qa];B[oa];W[ma];B[oa];W[na];B[sa];W[jb];B[oa]C[RIGHT]))
(;W[qa];B[oa];W[nb];B[rb];W[ma];B[oa];W[na];B[sa];W[jb];B[oa]C[RIGHT]))
(;B[qa];W[sd])
(;B[rb];W[qa]
(;B[na];W[oa])
(;B[sa];W[oa])))
(;B[qa];W[sd]C[Dead shape for black.])
(;B[ra];W[sb]C[Black is simply dead.])
(;B[sd];W[rb]
(;B[sb];W[ra]
(;B[qa];W[rc])
(;B[rc];W[qa]))
(;B[qa];W[sb])
(;B[ra];W[sb]))
(;B[sc];W[rb])
(;B[rb];W[sc]
(;B[sd];W[sb]
(;B[qa];W[sa]
(;B[na];W[nb]C[This is bent four in the corner (Black is dead under japanese rules and nearly dead under other rule sets).])
(;B[oa];W[nb]C[This is bent four in the corner (Black is dead under japanese rules and nearly dead under other rule sets).]))
(;B[na]C[NOTTHIS])
(;B[sa];W[qa];B[na];W[nb]))
(;B[sb];W[sd])
(;B[qa];W[sd])
(;B[na]C[NOTTHIS])))