<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 70-year-old man presents to a physician with a cough and difficulty breathing during the last 7 years. He has smoked since his teenage years and regularly inhales tiotropium, formoterol, and budesonide and takes oral theophylline. The number of exacerbations has been increasing over the last 6 months. His temperature is 37.2C 99F, the heart rate is 92min, the blood pressure is 13488 mm Hg and the respiratory rate is 26min. On chest auscultation breath sounds are diffusely decreased and bilateral rhonchi are present. Pulse oximetry shows his resting oxygen saturation to be 88. Chest radiogram shows a flattened diaphragm, hyperlucency of the lungs, and a long, narrow heart shadow. The physician explains this condition to the patient and emphasizes the importance of smoking cessation. In addition to this, which of the following is most likely to reduce the risk of mortality from the condition?? A: Low-dose oral prednisone, B: Prophylactic azithromycin, C: Roflumilast, D: Pulmonary rehabilitation, E: Supplemental oxygen,  <response>: This is a patient with chronic obstructive pulmonary disease COPD based on the description of long-term smoking history, medications he is taking, and clinical findings of cough, dyspnea, wheezing, and hypoxemia. The question asks about an additional intervention that would reduce his mortality risk. Choices include prednisone, azithromycin, roflumilast, pulmonary rehabilitation, and supplemental oxygen. Prednisone may help acutely but has not been shown to reduce mortality. Azithromycin may help reduce exacerbations but has not been shown to reduce mortality. Roflumilast is a phosphodiesterase inhibitor that can help reduce exacerbations but has not been shown to reduce mortality. Pulmonary rehabilitation can improve quality of life but has not been definitively shown to reduce mortality. Supplemental oxygen for hypoxemic COPD patients has been clearly shown in multiple studies to reduce mortality.E: Supplemental oxygen 