This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory, Subject name: Medicine
Which of the following is contributory factor for developing Cor-pulmonale in chronic bronchitis 
Select and explain. 
A. Hypoxia, B. Hypercapnea, C. Acidosis, D. Alkalosis
A: Hypoxia
Answer: A: Hypoxia 
Explanation: (Hypoxia) (1453-54-H17th)COR- PULMONALE - denotes RV hypertrophy and eventual failure resulting from pulmonary disease and the attendent hypoxia or from pulmonary vascular diseaseEssentials of Diagnosis - Cor pulmonale* Symptoms and sign of chronic bronchitis and pulmonary emphysema* Elevated JVP, Parasternal lift, edema, hepatomegaly ascites* ECG shows tall, peaked P waves (P- pulmonale) right axis deviation, and RVH* Chest radiograph : enlarged RV and PA* Echocardiogram or radionuclide angiography excludes primary LV dysfunctions