(No. 206: Apr. 3, 2000)
Elementary level: Answer
The calm move Black 1 is crucial.
There is no way for White to live.
Elementary level: Wrong Answer 1
Black 1 lets White get a Ko with 2 to 4.
Elementary level: Wrong Answer 2
Black 1 also allows White to get a Ko with 2 to 6.
Intermediate level: Answer
Black wins the capturing race with 1 and 3.
Intermediate level: Wrong Answer
Black 1 allows White to win the capturing race with 2.