The phospholipids of plasma membranes are amphipathic: they have both hydrophilic and hydrophobic regions. The hydrophobic core of the plasma membrane helps some materials move through the membrane, while it blocks the movement of others. How does the structure of the cell membrane help to enable its function? A) The double layer of phospholipids positions the hydrophilic lipid tails on the inside, away from the external environment and the the watery cytoplasm. B) The double layer of phospholipids positions the hydrophilic lipid tails on the outer edge towards the external environment and on the inner side towards the watery cytoplasm. C) The double layer of phospholipids positions the hydrophilic phosphate heads on the outer edge towards the external environment and on the inner side towards the watery cytoplasm. D) The double layer of phospholipids positions the hydrophobic phosphate heads on the outer edge towards the external environment and on the inner side towards the watery cytoplasm.