What Would Happen If the Plasma Membrane Were Composed Solely

What would happen if the plasma membrane were composed solely of phospholipids and no proteins?

A) Immune reactions would not be affected.
B) The movement of molecules across the membrane would not be affected.
C) All movement of molecules across the membrane would cease.
D) Simple diffusion and osmosis would continue to occur.
E) Only water would be able to pass through the membrane.