is the most plausible move, but is the tesuji for w and white can make two eyes at a.
So b should find a way to prevent two eyes at a by sente.
unkx80: I seem to recall reading somewhere that is the best resistance, and as a result, the best Black can do is to capture the stones and let White live.
The flaw occurs in hhw's variation. Unlike the above variation, white is alive in the original problem.
unkx80: Thanks shevious. I posted that variation in a hurry without verification, and now I am caught with my pants down.
shevious: Your recalling was almost correct and quite helpful. I didn't realize the flaw of the original shape until you and hhw commented about the variations.