In a typical mammalian plasma membrane, where is cholesterol primarily located within the lipid bilayer?

• A. Intercalated between phospholipid fatty acid tails in both leaflets of the bilayer
• B. Confined to the cytosolic surface as a peripheral lipid bound to cytoskeletal proteins
• C. Present only within transmembrane protein channels to line their hydrophilic pores
• D. Covalently attached to the polar head groups of phospholipids on the extracellular leaflet only

Answer: (A)