The correct answer is (a) Phosphatidyl choline
For explanation I would say: The phospholipids of cell membrane are composed of phosphatidyl choline (PC), phosphatidyl serine (PS), phosphatidyl ethanolamine (PE) and phosphatidyl inositol (PI). PC is exoplasmic and present towards the extracellular fluid. PS, PE and Pi are cytosolic and located towards the cytoplasm.
