(;
AB[ec][cd][rc][qc][pd][od][ne][qe][pp][op][oq][kq][dp][cp][dq][bo][fp][er][ds][pj]
AW[cg][cj][bp][aq][br][cq][cr][dr][pq][qq][ro][pn][qi][qb][pc][oc][nd][md][lc]
TR[pj]
C[White's response to the marked play?

Source:
   Attack and Defense, Ch. 7, pp. 172-173
   Akira Ishida & James Davies, Ishi Press];
LB[pf:C][qj:B][pi:A]
C[Hint:  White A, B, or C?]
(;
W[pi]
C[A bad response.];
B[oj];W[oi];B[nj];W[rk];B[nn]
C[Black's stones are working perfectly.]
)
    (;
    W[qj]
    C[Also leads to an inferior result.  White can do better.];
    B[pl]
    (;
    W[pk];B[ok];W[qk];B[on]
    C[Black flattens out White's framework while expanding his own.]
    )
        (;
        W[nn]
        C[White can jump out to prevent a large framework, but ...];
        B[qk]
        LB[qn:A]
        C[... Black weakens the 2 stones above, and threatens the cut at A.  This result is not good for White either.]
        )
    )
    (;
    W[pf]
    C[The correct response.]
    (;
    B[rb]
    C[A good response.];
    W[oe];B[qj];W[nf]
    C[A surprising but good result for White.]
    )
        (;
        B[of]
        C[White is hoping for this response.];
        W[og];B[ng];W[nh];B[oh];W[oi];B[pg];W[pi]
        TR[pj]
        C[White has an excellent result.  Black's marked shoulder hit has failed.]
        )
    )
)

