Final answer:
Lipid-anchored proteins are usually found on the extracellular side of the plasma membrane and are covalently attached to membrane lipids.
Step-by-step explanation:
Lipid-anchored proteins can be found on either side of the plasma membrane, but for the question's provided options, the correct answer is: A) Extracellular side; covalent attachment to lipids. Lipid-anchored proteins are typically attached to the membrane lipids through covalent bonds, such as thioester or amide bonds, often to a glycosylphosphatidylinositol (GPI) anchor or through fatty acid chains like myristate or palmitate. While membrane proteins can be found both inside and outside the cell, the extracellular side of the membrane often has lipid-anchored proteins connected covalently to lipids, interacting with elements such as the extracellular matrix and involved in cellular signaling.