Correct option is D
Phospholipids are the primary lipid components of mammalian plasma membranes, forming the lipid bilayer. The major phospholipids include:
(a) Phosphatidylinositol– Involved in cell signaling and membrane structure.
(b) Phosphatidylserine– Important for apoptosis and membrane asymmetry.
(c) Sphingomyelin– A sphingolipid that contributes to membrane stability.
Cholesterol (d) is a sterol, not a phospholipid. While it is a crucial component of plasma membranes (modulating fluidity and stability), it is not classified as a phospholipid.
Thus, the correct answer is(d) Cholesterol.
