COPD患者长期家庭氧疗的适应证为

A.PaO2≤55mmHg或SaO2≤88%

B.PaO2≤60mmHg或SaO2≤90%

C.PaO2≤50mmHg或SaO2≤90%

D.PaO2≤60mmHg或SaO2≤88%

E.PaO2≤55mmHg或SaO2≤90%