Which of These Statements Describes the Plasma Membrane

Which of these statements describes the plasma membrane

A) Under a light microscope, it appears as a trilaminar structure.
B) The carbohydrates on the outer surface serve as receptor sites for binding chemical messengers in the environment of the cell.
C) The lipid bilayer serves as a barrier to the passage of H₂Oa.-soluble substances through the membrane.
D) Carrier proteins shuttle back and forth across the membrane as they carry passenger molecules from one side to the other.