EVENT
BOARDSIZE 19
SETUP W D17 P17 R10 R5 
SETUP B R16 Q15 Q3 C4 
MARK \t@R10
COM
Problem 28. Black to play.  

After White has extended with her marked stone, what should Black
do ? 
ENDCOM
B 1 P4
MARK A@O4
USER
CORRECT ANSWER
ENDUSER
COM
Correct Answer.

Black should play another diagonal move with 1 or play the knight's
move at A.
ENDCOM
  VAR
  B 1 O4
  USER
  CORRECT ANSWER
  ENDUSER
  COM
  Correct Answer.

  Also correct.
  ENDCOM
  ENDVAR