Which of the following statements about membrane lipids is true?
a. glycerophospholipids contain 2 fatty acids linked to c-1 and c-3 of glycerol.
b. all sphingolipids are glycolipids that lack phosphate groups.
c. galactolipids have 1 or 2 galactose residues connected to glycerol by glycosidic linkages and are predominate in plant cells.
d. sphingolipids are composed of 1 sphingosine (or its derivative), 2 fatty acids, and 1 polar head group.
e. archaea contain membrane lipids that contain 2 long alkyl chains ester-linked to glycerol at both ends.