A Primary Function of Cholesterol in the Plasma Membranes of Some

A primary function of cholesterol in the plasma membranes of some animals is to

A) make the membrane more rigid, allowing it to resist pressure from outside the cell.
B) facilitate the removal of hydrogen atoms from saturated phospholipids.
C) facilitate cell-cell interactions by binding to receptors on neighboring cells.
D) enable the membrane to stay fluid more easily when the temperature drops.