It is best to keep destructive actions away from other actions. Even when you have a confirmation for your destructive actions, not accidentally clicking them is the better route then having to cancel out of a confirmation. This means Option B would limit user frustration.
I would recommend swapping the buttons in Option B:
This is because your combo boxes are on the left side and the user does not have to cross the horizontal table length with their eyes or the mouse in order to select multiple boxes and then click the edit. Having to do this for the delete action also makes it more difficult to accidentally click the button.
I'd also suggest duplicating the buttons on the bottom of the table. Might look weird for a shorter table, but not having to scroll to the top would be appreciated by users when interacting with longer tables.
You can also add single row actions on mouse over, again placing the edit & delete buttons appropriately as to avoid accidental activations.
(note that my placement in the above example wouldn't be the best, just an example)
For similar examples and suggestions, see answers to the following question: Many buttons on the page, ways to improve?