Plz ans the question

Plz ans the question •e ngure shows a diagrammatic view of human respiratory system with labels A, B, C and D. Select the option which gives correct identification and main function and/or characteristic • Bronchus Cut end of ri Lung c (1) D — Lower end of lungs — diaphragm pulls it down during inspiration (2) A — trachea - long tube supported by complete cartilaginous rings for conducting inspired air (3) B — pleural membrane - surround ribs on both sides to provide cushion against rubbing (4) C — Alveoli - thin walled vascular bag like structures for exchange of gases