Answer:
A. play a role establishing and maintaining membrane lipid asymmetry
Step-by-step explanation:
Proteins that move move certain phospholipids between leaflets are transmembrane proteins via "flip-flop" transition have also the possibility to maintain membrane lipid asymmetry. There are few types of such proteins:
- flipases-move lipids from the exterior to the interior side of the membrane, energy required
- flopases-move lipids in reverse comparing to flipases, energy required
- scramblases-no energy required, bidirectional
Because of the action of those proteins, cytosolic side of plasma membrane differs from exoplasmic side (asymmetry).