This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'High Altitude Pulmonary Edema; True is \nSelect and explain. \nA. Occurs due to raised pulmonary capillary pressure, B. Occurs due to high permeability of pulmonary capillary, C. Leads to leakage of proteins and WBC, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The High Altitude Pulmonary Edema (HAPE) is due to raised pulmonary capillary pressure and high\xa0 permeability of pulmonary capillary. This leads to leakage of proteins and white blood cells.\nHigh-altitude\xa0pulmonary\xa0edema\xa0is\xa0a\xa0patchy\xa0edema of the lungs that is related to the marked pulmonary \u200bhypertension that develops at high altitude. It has been argued that it occurs because not all pulmonary arteries have enough smooth muscle to constrict in response to hypoxia, and in the capillaries supplied by those arteries, the general rise in pulmonary arterial pressure causes a capillary pressure increase that disrupts their walls (stress failure). \u200b\nIn\xa0high-altitude\xa0pulmonary\xa0edema,\xa0prompt\xa0treatment with O2\xa0 is essential-and, if available, use of a hyperbaric chamber.\xa0Portable\xa0hyperbaric\xa0chambers\xa0are\xa0now\xa0available in a number of mountain areas. Nifedipine, \u200ba Ca2+\xa0 channel blocker that lowers pulmonary artery pressure, can also be useful.\nReference: Ganong’s Review of Medical Physiology 25 Ed page no 649\u200b', 'role': 'assistant'}]