<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A previously healthy 64-year-old woman comes to the physician because of a dry cough and progressively worsening shortness of breath for the past 2 months. She has not had fever, chills, or night sweats. She has smoked one pack of cigarettes daily for the past 45 years. She appears thin. Examination of the lung shows a prolonged expiratory phase and end-expiratory wheezing. Spirometry shows decreased FEV1:FVC ratio 70 predicted, decreased FEV1, and a total lung capacity of 125 of predicted. The diffusion capacity of the lung DLCO is decreased. Which of the following is the most likely diagnosis?? A: Bronchial asthma, B: Bronchiectasis, C: Hypersensitivity pneumonitis, D: Interstitial lung disease, E: Chronic obstructive pulmonary disease,  <response>: This is a patient with chronic cough, shortness of breath, and a smoking history. The key findings on exam are prolonged expiratory phase, end-expiratory wheezing, decreased FEV1FVC ratio, and decreased DLCO. These indicate an obstructive lung disease. The increased total lung capacity indicates air trapping, also consistent with obstruction. The smoking history makes chronic obstructive pulmonary disease COPD most likely. Bronchial asthma is less likely in an older smoker. Bronchiectasis, hypersensitivity pneumonitis, and interstitial lung disease would not cause airway obstruction.E: Chronic obstructive pulmonary disease 