After the advent of the electron microscope in 1950 a detailed structure of the cell membrane was studied. An improved model of the structure of cell membrane proposed by Singer and Nicolson (1972) was widely accepted as fluid mosaic model. Identify the correct statement w.r.t. the fluid mosaic model.

The quasi-fluid nature of lipid enables lateral movement of proteins within the overall bilayer. This ability to move within the membrane is measured as its fluidity.
The integral proteins are partially or totally buried in the membrane.
In addition to phospholipids membrane also contains cholesterol.
The major lipids are phospholipids that are arranged in a bilayer.