Which statement best describes how chronic lung diseases contribute to pulmonary hypertension and cor pulmonale?

• A. Hypoxic vasoconstriction in chronic bronchitis and CF; obliteration of parenchyma in emphysema increases pulmonary vascular resistance
• B. Pulmonary hypertension always results from elevated left atrial pressure
• C. Pulmonary hypertension is defined by decreased pulmonary vascular resistance
• D. Right heart failure occurs only with systemic hypertension

Answer: (B)