(;AW[ib][jb][ob][ec][jc][nc][dd][kd][nd][ce][de][fe][ke][ef][ff][gf][kf][rf][hg][bh][eh][fh][hh][qh][bi][ii][ki][cj][fj][gj][ij][jj][pj][qj][ck][nk][pk][rk][rl][dm][fo][go][mo][cp][dp][fp][mp][op][qp][cq][oq][dr][pr]AB[hb][kb][cc][gc][pc][bd][cd][hd][be][ge][le][ne][oe][qe][cf][hf][if][jf][lf][bg][cg][gg][lg][ih][jh][ci][di][ei][bj][kj][ek][fk][gk][ik][jk][lk][ok][qk][ml][nl][pl][pm][qm][rm][gp][hp][lp][dq][eq][fq][mq][nq][er][nr][or]LB[on:1]C[In the previous problem White played 1. This was a mistake where should he have played?]PL[W];W[po]CR[po];B[ro]CR[ro];W[rp]CR[rp];B[ps]CR[ps];W[qr]CR[qr];B[lo]CR[lo];W[ho]CR[ho];B[io]CR[io];W[in]CR[in];B[jo]LB[db:A][pb:B][re:C]CR[jo]C[CHOICE RIGHT Great! white now has sente and can play A, B or C.])