In the context of the lipid bilayer, what is the primary function of carbohydrates attached to membrane lipids and proteins on the extracellular surface?

• A. They form the hydrophobic core of the membrane that prevents ion leakage.
• B. They mediate cell-cell recognition and adhesion and can act as identification tags for signaling.
• C. They actively transport ions across the membrane by hydrolyzing ATP.
• D. They serve as the main structural filaments that maintain cell shape from within the cytoplasm.

Answer: (B)