Beginner Exercise 191 / Solution

Solution  

Black must prevent White's main threat, atari at a. The only correct solution is .

Continuation 1  

If here, then captures and lives.

Continuation 2  

If makes a throw-in, captures and lives. Beware, at a is a blunder - it's a snapback.

Failure 1  

fails to , since Black will not be able to avoid a ko. See Beginner Exercise 194 for more.

Failure 2  

at the corner is still worse - renews the threat and at a dies in gote.