EVENT
BOARDSIZE 19
SETUP W F17 F16 K17 R16 
SETUP B D16 E17 D14 N17 Q16 R15 R10 
MARK 1@R15 \t@R16
COM
Problem 133. White to play.  

This time Black responds to the marked stone by blocking on the
outside with 1. What is White's response here ? 
ENDCOM
W 1 S15
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

Playing hane underneath with 1 is the proper move.
<=
ENDCOM
  VAR
  W 1 R17
  USER
  CORRECT ANSWER
  ENDUSER
  COM
  Correct Answer.

  It is also possible for White to play 1 here.
  <=
  ENDCOM
  ENDVAR