Answer:
(B) They make up structural parts of cell membranes.
Step-by-step explanation:
Lipids are one of the major biomolecule and acts as a semi- permeable membrane for the passage of molecules.
Lipids are the major constituent of the cell membrane. Lipid is present as bi layer membrane and maintains the fluidity of cell membrane. Hence, lipids makes the structural component of the cell membrane.
Thus, the correct answer is option (B).