Worst Move Problem 5 / Solution

White to die in gote  

MrTenuki: After , the group cannot live or connect out even if white adds a, b, c, or d later, unless black plays tenuki twice.

Case D  

is better here rather than at a, because this prevents white from approaching from either side (and playing at b allows white to live with a).

Case E  

(This is not a seki, as white would be forced to connect at a if the outside liberties are filled.)