In a high-temperature environment, how does cholesterol affect the lipid bilayer?

• A. Cholesterol decreases rigidity to allow the membrane to become more fluid.
• B. Cholesterol decreases permeability to prevent substances from passing through.
• C. Cholesterol increases permeability to allow more substances to pass through.
• D. Cholesterol increases rigidity to prevent the membrane from becoming too fluid.

Answer: (D)