(;AB[sb]AB[qa]AB[rc]AB[qc]AB[qd]AB[pd]AB[od]AB[nd]AB[nc]AB[nb]AB[lb]AW[rb]AW[qb]AW[pc]AW[oc]AW[ob]AW[oa]AW[pa]C[Black to kill.]AP[goproblems]
(;B[ra];W[sa];B[ra]C[White only has one eye. White is dead.RIGHT])
(;B[sa]
(;W[ra]C[White is lives.CHOICE])
(;W[sc]C[A ko threat.CHOICE];B[sd];W[ra]C[White has two eyes and lives.];B[sc])))