Black can connect with 1, his damezumari is eliminated, and white gets dies. Therefore...
Assuming black cannot fight the ko for everything in corner after the 1/2 exchange, if black plays one they will lose three stones since they cannot connect after the sequence to 6.
If white 2 here black can kill white with 3. White is the one in damezumari here, unable to atari from either side.
This is the best sequence for both, white secures a small life in the corner in gote.
tapir: i tried this a while ago but didn't achieve any publishable result... isn't there always a ko possibility (against 7-2 cut) to reckon with? sure it is flower viewing for white, but it shouldn't be dismissed without mentioning.
shevious: For White , Black's will kill entire White.
White's correct response for Black is a.