(;AB[bs]AB[cr]AB[cq]AB[cp]AB[bq]AB[bo]AB[bn]AW[bp]TR[bp]AW[am]AW[bm]AW[cm]AW[cn]AW[co]AW[dp]AW[dq]AW[dr]AW[fr]AP[goproblems]
(;W[ar];B[ap]
(;W[an]C[RIGHT])
(;W[aq];B[an]))
(;W[an]
(;B[ar]LB[ap:A]C[CHOICE])
(;B[ap]C[This is a mistake by Black that reverts to the solution];W[ar]C[RIGHT]))
(;W[ao]
(;B[ap]C[CHOICE];W[an];B[ar])
(;B[ar]C[Also possible for black];W[an];B[aq])))