Treatment of an abscess often requires that it be surgically drained because ______.
O the wall of the abscess prevents proper blood flow into the pus
O the wall of the abscess prevents proper elimination of wastes from the enclosed pus
O the wall of the abscess prevents neutrophils from entering the pus and attacking the pathogens
O the wall of the abscess prevents macrophages from differentiating into monocytes in the pus