Right option is (b) Phosphatidyl serine (PS)
Easiest explanation: PS, concentrated in the inner leaflet of cell membrane, has a negative charge at physiologic pH and thus binds positively charged amino acid residues of lysine and arginine. The appearance of PS on the outer surface of aging lymphocytes marks the cells for destruction by macrophages. Appearance of PS on the outer surface of platelets can lead to blood coagulation.