In the fierce attack, the enemies were completely wiped . . . . . . . .

The correct answer is A. The word “wiped out” means to destroy or kill completely. In the context of the question, the enemies were completely destroyed in the fierce attack.

The other options are incorrect because they do not mean to destroy or kill completely. The word “wiped off” means to remove something from a surface. The word “wiped away” means to remove something by wiping it with a cloth or other object. The word “wiped over” means to cover something with a cloth or other object.