Which description correctly states roles of phospholipids and cholesterol in cell membranes?

Phospholipids form a bilayer that creates a semi-permeable barrier; cholesterol intercalates in the bilayer modulating fluidity and serves as precursor for steroid molecules like vitamin D and sex hormones.

Phospholipids dissolve membrane proteins to allow free diffusion of ions, and cholesterol is the main transporter of fat-soluble vitamins in the bloodstream but not a membrane component.

Phospholipids produce ATP in the membrane while cholesterol acts exclusively as a storage form of carbohydrate and is not involved in hormone precursor pathways.

Cholesterol forms the outermost carbohydrate coat of the membrane, and phospholipids are only involved in intracellular signaling unrelated to membrane structure.