Cell Membranes Are Made Up of Phospholipid Molecules Arranged in

Cell membranes are made up of phospholipid molecules arranged in

A) two layers with their negatively charged heads forming the inner and outer surfaces.
B) a single layer with their hydrophobic tails facing inward.
C) two layers with their positively charged heads forming the inner and outer surfaces.
D) two layers with their positively charged tails forming the inner and outer surfaces.