What is the function of the cholesterol molecules in a cell membrane?
a. they make it thicker.
b. they make it porous.
c. they make it more fluid.
d. they make it less flexible.

C. THEY MAKE IT MORE FLUID.

Cholesterol molecules are important in maintaining the consistency of the cell membrane. They are made up of four rings of hydrogen and carbon atoms. They are hydrophobic and are found among the hydrophobic tails in the lipid bilayer. They keep phospholipid tails from coming into contact and solidifying. They ensure that the cell membrane stays fluid and flexible.

Reproduction i think

Distillation.  distillation is the correct answer.