This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Physiology
With increase in age which of the following is true for lungs? 
Select and explain. 
A. Pulmonary compliance increases, B. Residual volume decreases, C. Mucociliary clearance increases, D. Fibrous of interstitium decreases
A: Pulmonary compliance increases
Answer: A: Pulmonary compliance increases 
Explanation: Anatomical and Physiological changes of respiratory system with ageing: Anatomical Air space size: Increased Compliance Chest wall compliance : Decreased Lung compliance: Increased to unchanged Total respiratory system compliance: Decreased Muscle strength Maximum inspiratory pressure(MIP): Decreased Trans diaphragmatic pressure (Pdi): Decreased Maximum voluntary ventilation (MVV): Decreased Lung Function FEV1: Decreased FVC: Decreased TLC: Unchanged Vital capacity: Decreased Functional residual capacity: Increased Residual volume: Increased DLCO/VA: Decreased Excercise capacity VO2 max: Decreased Dead space ventilation: increased Immunology Bronchial fluid Neutrophils %: Increased Ratio of CD4+/CD8+ cells: Increased Epilthelial lining fluid antioxidants: Decreased Ref: Guyton and Hall Textbook of Medical Physiology 13th edition Pgno: 499