A collection of air between the chest wall and lungs that causes the lungs to collapse is known as:

A) pneumonitis.
B) pneumothorax.
C) pneumonia.
D) pneumoconiosis.

A pneumothorax is a condition where air is trapped between the chest wall and the lung, causing the lung to collapse. Pneumonitis refers to inflammation of the lungs, pneumonia is an infection that causes inflammation of the lungs, and pneumoconiosis is a lung disease caused by inhaling dust or other particles. None of these are specifically related to the collection of air between the chest wall and lungs.