Keeping in view the "fluid mosaic model" for the structure of cell membrane, which one of the following statements is correct with respect to the movement of lipids and proteins from one lipid monolayer to the other (described as flip- flop movement)?

Question

( A ) While lipids can rarely flip-flop proteins cannot
( B ) While proteins can flip-flop, lipids cannot
( C ) neither lipids, nor proteins can flip-flop
( D ) Both lipids and proteins can flip-flop