<prompt> Lungs do not collapse during expiration because of the presence of?Hyaline membraneDipalmitoyl phosphatidyl cholineMacrophagesInterstitial fluid  <response>: b. Dipalmitoyl phosphatidyl cholineRef: Ghai 8e p 169-170Dipalmitoyl phosphatidyl choline is an important constituent of Surfactant, which prevent alveolar collapse during expiration. 