All other moves than lose territory.
rubilia: Are you sure black cannot live in the corner? If she could, there should be better moves than to . Do you leave this question open by purpose? I suppose a white stone somewhere in the corner (at b17 for instance) would make the problem a clearer "monkey jump" one.
If Black can play a ko with , White gets a disaster as a result. Otherwise, Black can play at a and still get a much better result than in the correct line of play.
Zappastian: What if black continues to attack like this?
xela: It's the same as the question rubilia asked above (and that noone has answered yet): can black live in the corner? I think the answer is probably not, but I'm not entirely sure: this sort of thing can get complicated, especially if there is a black stone near a.
-- GoJaC, 23kyu
Thanks! -- GoJaC