EVENT
BOARDSIZE 19
SETUP W D16 E15 F15 G16 G17 H14 Q4 L4 K7 H2 F6 F7 E5 E4 E3 C3 C2 
SETUP B C17 C16 E18 F17 F16 L16 P17 R16 R10 H4 G6 B3 C4 D4 D6 D7 C10 C14 
MARK A@P11 B@P10 C@P9
COM
Problem 140. White to play.  

Black has made a big profit on the left side and has mapped out
a huge moyo on the right, so it is urgent for White to reduce
this moyo, but which point should she play: A, B, or C ? 
ENDCOM
W 1 P9
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

White expands her moyo with 1 while limiting the size of Black's.
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  VAR
  W 1 P11
  COM
  Failure.

  If White plays 1, ...
  ENDCOM
  B 2 Q9
  COM
  ... Black will respond with 2, and, ...
  ENDCOM
  W 3 R11
  B 4 S11
  W 5 R12
  B 6 S12
  W 7 R14
  B 8 O10
  COM
  ... with the sequence to 8, White's moyo has been greatly reduces
  and her stones in the upper right are under attack.
  <=
  ENDCOM
  ENDVAR
B 2 Q8
W 3 P8
B 4 Q7
W 5 P7
B 6 Q6
COM
Even though Black gains some profit up to 6, ...
ENDCOM
W 7 P6
COM
... the scale of White's moyo is enough to maintain the balance
of territories.
<=
ENDCOM