Question ID:PT29 S1 Q15 Passage:Ordinary mountain sickness, a common condition among mountain climbers, and one from which most people can recover, is caused by the characteristic shortage of oxygen in the atmosphere at high altitudes.  Cerebral edema, a rarer disruption of blood circulation in the brain that quickly becomes life-threatening if not correctly treated from its onset, can also be caused by a shortage of oxygen.  Since the symptoms of cerebral edema resemble those of ordinary mountain sickness, cerebral edema is especially dangerous at high altitudes. Stem:Which one of the following is an assumption on which the argument depends? Correct Answer Choice:AChoice A:The treatment for ordinary mountain sickness differs from the treatment for cerebral edema. Choice B:Cerebral edema can cause those who suffer from it to slip into a coma within a few hours. Choice C:Unlike cerebral edema, ordinary mountain sickness involves no disruption of blood circulation in the brain. Choice D:Shortage of oxygen at extremely high altitudes is likely to affect thinking processes and cause errors of judgment. Choice E:Most people who suffer from ordinary mountain sickness recover without any special treatment.