<prompt> Pulmonary hypeension in COPD is due to all, Except:HypoxiaPulmonary vasoconstrictionHigh lung volumeBronchoconstriction  <response>: Answer is D Bronchoconstriction Bronchoconstriction is not a cause for Pulmonary Hypeension Pulmonary Hypeension in COPD has been attributed to multiple factors including: Hypoxia Pulmonary vasoconstriction secondary to hyoxia Acidemia Hypercapnia Mechanical effect of high lung volume on pulmonary vessels Loss of small vessels in vascular bed Regions of emphysematous lung destruction 