(;AB[jc]AB[kc]AB[ld]AB[md]AB[nd]AB[nc]AB[od]AB[pd]AB[qd]AW[kb]AW[lc]AW[mc]AW[nb]AW[oc]AW[pc]C[Black's stones are strong while white's group has some obvious weaknesses. What is the best way to attack this white group?]AB[hc]AB[qf]AP[goproblems]
(;B[pb]
(;W[ob]
(;B[qb]C[];W[jb];B[ib]C[Nice! The white group cannot live.CHOICERIGHT])
(;B[qc];W[qb];B[rb];W[pa]))
(;W[mb]
(;B[ob];W[la]C[Black captures the corner in sente (compare with variations).CHOICERIGHT])
(;B[qb];W[la];B[ob]C[Gote for black.])))
(;B[ob];W[pb];B[mb];W[oa];B[lb];W[qc]C[Black captures two stones but white is alive with points.])
(;B[mb];W[lb];B[ob];W[ma];B[pb]C[Black captures the corner but white is alive and has sente.])
(;B[qc];W[pb]C[White keeps all his stones!])
(;B[qb];W[pb]
(;B[pa];W[oa]
(;B[qa];W[ma]C[White is alive and well.])
(;B[mb];W[qa]
(;B[lb];W[qc])
(;B[qc];W[lb]))
(;B[ma];W[mb]
(;B[qa];W[la])
(;B[la];W[qa])))
(;B[qc];W[oa]))
(;B[jb];W[qc];B[rc];W[rb];B[mb];W[ob])
(;B[lb];W[mb])
(;B[na];W[ob])
(;B[ma];W[mb]
(;B[pb];W[qb])
(;B[qb];W[pb];B[pa];W[oa]
(;B[qa];W[la])
(;B[la];W[qa]))))