(;
GM[1]
SZ[19]
AW[dd][jd][nc][dp][po][no][qq][pr]
AB[pd][pf][qk][pq][fq][jp][np][mo][qr]
LB[no:1][mo:2][qq:3][qr:4][pr:5]
TR[qk]
C[Problem 31. Black to play.  

Black has played the low Chinese opening with the marked stone. How should Black respond to White 5 ? ]
;B[pp]
TR[qk]

TE[2]
C[Correct Answer.  

With the marked stone on the third line in place, bumping against the white stone with Black 1 is the best move. ]
;W[qp];B[rr];W[qn];B[nq]
LB[rk:B][pk:A]
TR[qk]
C[The sequence to Black 5 is now inevitable, and White's group is still under attack.  

Comparison.  

If Black had played the high Chinese opening with the marked stone at A, White could easily settle her group by sliding to B. <= ]
)
)