Reuven The question we should really look into is, wherether White can kill. Since a black move at an instinctive point such as a would surely create a good enough division of the corners eye space, providing life.
Reuven In the following 2 diagrams, the location marked with a square serves as an intuitive and simple refutation to the attacks.
Reuven Only move that's left to try is a to which Black responds with b keeping his eye-space large enough to preserve the miai of the locations marked with squares.
Reuven At this point, it's obvious that the original group is safe as it is.
However it's interesting to add that with the presence of a stone such as $$W the groups status would be decided only when one of the players adds a move.