(;AW[ab]AW[bb]AW[cc]AW[dc]AW[fb]AW[gb]AB[bc]AB[bd]AB[cd]AB[dd]AB[ed]AW[ec]AB[fc]AB[gc]AB[hc]AB[hb]AB[ha]C[Black to kill]AP[goproblems]
(;B[da]
(;W[eb]C[CHOICE];B[cb];W[db];B[ba]C[]
(;W[ca]C[Ko, good job!RIGHT])
(;W[ea]C[Ko, good job!... but what if white goes here?CHOICE];B[ca];W[aa]
(;B[ca];W[ga];B[cb]C[RIGHT])
(;B[ga];W[ca])))
(;W[ca];B[eb];W[cb];B[fa]C[RIGHT])
(;W[ea];B[cb];W[eb];B[ga]C[RIGHT]))
(;B[db];W[eb]
(;B[ga];W[da]C[White is alive])
(;B[cb];W[ca]C[White is alive]))
(;B[eb];W[db]
(;B[ca];W[da];B[ba];W[ea]C[White is alive])
(;B[ea];W[da]C[White is alive]))
(;B[fa];W[da]
(;B[ca];W[ba];B[db];W[cb]C[White is alive])
(;B[eb];W[db]C[White is alive]))
(;B[ga];W[ca]
(;B[da];W[ea]C[White is alive])
(;B[eb];W[db]C[White is alive])
(;B[db];W[eb];B[ea];W[cb]C[White is alive]))
(;B[ea];W[ca]
(;B[eb];W[db]C[White is alive])
(;B[da];W[fa]C[White is alive])
(;B[db];W[eb]C[White is alive]))
(;B[ba];W[da]
(;B[eb];W[db]C[White is alive])
(;B[cb];W[db];B[ca];W[aa]C[White has a miai to make life]LB[ca:A]LB[ga:B])
(;B[ca];W[eb];B[cb];W[db];B[ga];W[aa]C[White has a miai to make life]LB[ca:A]LB[fa:B])
(;B[ga];W[db]C[White has a miai to make life]LB[ca:A]LB[fa:B]))
(;B[ca];W[ba]
(;B[cb];W[db]C[White is alive])
(;B[eb];W[db];B[ea];W[cb]C[White is alive])
(;B[ea];W[eb]
(;B[ga];W[fa];B[cb];W[da]C[White is alive])
(;B[cb];W[da]C[White is alive]))))