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
Which one of the following acts as lung surfactant: 
Select and explain. 
A. Sphingomyelin, B. Lysolecithin, C. Dipalmitoyl lecithin, D. Cephalin
C: Dipalmitoyl lecithin
Answer: C: Dipalmitoyl lecithin 
Explanation: C Harper, 26th ed, p. 202 & 25th ed, p. 265