Why Is a Cell Membrane Like a Phospholipid Sandwich

Why is a cell membrane like a phospholipid sandwich?

A) The lipid is the bread and proteins are the spread.
B) It is a two-layered semipermeable structure with heads on the outside,tails in the middle,and heads on the inside.
C) It is a two-layered semipermeable structure with tails on the outside,heads in the middle,and tails on the inside.
D) It is a two-layered semipermeable structure with tails on the outside,tails on the inside,and heads in the middle.
E) It is a one-layered semipermeable structure with heads on the outside and heads on the inside.