It is best to keep destructive actions away from other actions. Even when you have a confirmation of your destructive actions, not accidentally clicking them is the best way to go, then cancel a confirmation. It means Option B limit users' frustration.
I would recommend to swap the buttons of option B:
Indeed, your combo boxes are on the left side and the user does not need to cross the length of the horizontal table with his or her eyes or mouse to select multiple areas, then click on the modification. Having to do this for the delete action also makes it harder to accidentally click the button.
I also suggest duplicating the buttons at the bottom of the table. This may seem strange for a shorter table, but users would appreciate users who interact with longer tables.
You can also add single-line actions when you move the mouse, repositioning the edit and delete buttons appropriately to prevent accidental activation.
(note that my placement in the example above would not be the best, just an example)
For examples and similar suggestions, see the answers to the following question: Several buttons on the page, ways to improve?