Which description accurately describes the cell membrane? a. a single permeable layer of phospholipids that have hydrophobic heads and hydrophilic tails

b. a semi-permeable double layer of phospholipids that have hydrophilic heads and hydrophobic tails

c. a single permeable layer of phospholipids that have hydrophilic heads and hydrophobic tails

d. a semi-permeable double layer of phospholipids that have hydrophobic heads and hydrophilic tails

e. a barrier of polypeptides that prevents molecules from entering or leaving the cell