As the volume of the thorax increases, the pressure inside the thorax decreases. This causes air to enter the body. By what process is the volume of the thorax increased so that air is inhaled?
- Aby the diaphragm and the external intercostal muscles contracting
- Bby the diaphragm relaxing and the external intercostal muscles contracting
- Cby the diaphragm and the internal intercostal muscles contracting
- Dby the diaphragm relaxing and the internal intercostal muscles contracting