(;
GM[1]
SZ[19]
AW[cd][ed][ch][hc][qc][ob][pf][qf][qi]
AB[cj][jc][nd][pd][qe][rd][oc]
LB[oc:1]
C[Problem 140.White to play.  

How does White respond to Black 1 ? ]
;W[rc]
LB[qd:A]

TE[2]
C[Correct Answer.  

White 1 aims at A, ... ]
(;B[rf]
C[... so Black must defend with 2. ]
;W[nb]
C[Next White extends to 3, ending the sequence in good shape. <= ]
)
(;B[pb]
C[Failure.  

Black 2 is unreasonable. ]
;W[qd];B[re];W[pe]
LB[qd:3]
C[White pushes through with 3 and 5, winning three black stones in a capturing race. <= ]
)
)