During ventilation, the intercostal muscles and diaphragm both contract and relax. Which row gives the muscle actions that produce the greatest volume within the thorax?
- Ainternal intercostal muscles relax; diaphragm contract
- Binternal intercostal muscles relax; diaphragm relax
- Cinternal intercostal muscles contract; diaphragm contract
- Dinternal intercostal muscles contract; diaphragm relax