This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lipids, Subject name: Biochemistry
[{'content': 'Which one of the following acts as lung surfactant: \nSelect and explain. \nA. Sphingomyelin, B. Lysolecithin, C. Dipalmitoyl lecithin, D. Cephalin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C Harper, 26th ed, p. 202 & 25th ed, p. 265', 'role': 'assistant'}]