(
;
FF[4]
GM[1]
SZ[19]
AP[Jago:Version 4.16]
AB[od][qd][bc][cc][dd][de][cf][dg][ef][ee][oq][kq][dp][fp][cq]
AW[cd][ce][db][dc][eb][ed][fc][fe][gd][qg][qj][pn][qp][bp][cn][ck]
LB[ic:A][jc:B][kc:C][lc:D][mc:E]
C[If white is allowed to play at E, then white has a huge moyo at the top and the black's upper right corner is threathened. (Black to choose a point from A to E.)]
GN[goproblem_x01]
(
;
B[lc]
C[RIGHT
The ideal extension to check white's expansion, and yet not too near its thickness.]
)
(
;
B[kc]
;
W[mc]
TR[qg][qj]
C[This extension is too far. Black loses territory and the two marked stones limit black's influence.]
)
(
;
B[jc]
;
W[lc]
C[This extension is too far. Black loses territory and the two marked stones limit black's influence.]
TR[qg][qj]
)
(
;
B[ic]
;
W[kc]
C[This is the worst choice. The marked stone is too near white's thickness and gets attacked by white instead.]
TR[ic]
)
(
;
B[mc]
C[This move is too conservative. White can play at A and get a fairly big territory at the top.]
LB[kc:A]
)
)