Hypoxemia in emphysema is due to all except-

Emphysema is characterised by destruction of gas-exchanging air spaces i.e.,the respiratory bronchioles,alveolar ducts,and alveoli.As a result,physiological dead space increases.Loss of elastic tissue,inflammation and fibrosis in airway wall result in premature airway closure,gas trapping,and dynamic hyperinflation leading to changes in pulmonary and chest wall compliance.As a result,elastic recoil is reduced. Reference:Harrison's medicine-18th edition,page no:2154.