Answer:
The correct answer would be - 1925, phospholipid bilayer.
Explanation:
Gorter and Grendel performed an experiment in 1925 to extract lipids from blood cell and after extracting the protein they evaluated red blood cell membrane.
They found out that plasma membrane have two lipid layer and these lipids are made of phospholipids. Phospholipids are phosphate group that are attached with the lipid molecule.
Thus, the correct answer would be - 1925, phospholipid bilayer.
