This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamins and Minerals, Subject name: Biochemistry
[{'content': 'Which of the following minerals is a major component of biological membranes? \nSelect and explain. \nA. Potassium, B. Sodium, C. Calcium, D. Phosphorus', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Lipid bilayer is made up of phospholipids - Lecithin, Sphingomyelin, Phosphatidyl Inositol and Phosphatidyl serine. So, phosphorus is a major component of biological membranes.', 'role': 'assistant'}]