What is the primary structural difference between phosphatidylcholine and phosphatidylethanolamine?

• A. Phosphatidylcholine has a glycerol backbone, while phosphatidylethanolamine does not.
• B. Phosphatidylcholine has choline attached to the phosphate group, while phosphatidylethanolamine has ethanolamine.
• C. Phosphatidylcholine is a sphingolipid, while phosphatidylethanolamine is a glycerophospholipid.
• D. Phosphatidylcholine contains two fatty acids, while phosphatidylethanolamine contains one.

Answer: (B)