Select the correct statement.

The lungs are situated in the thoracic chamber which is anatomically an air-tight chamber. The thoracic chamber is formed dorsally (not ventrally) by the vertebral column. Negative pressure breathing occurs in humans. Contraction of the diaphragm and the external intercostal pressure creates a negative pressure (vacuum) in the lungs that draws air from the atmosphere. We cannot directly alter the pulmonary volume.