<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 45-year-old woman presents to the physician with a 6-month history of progressive shortness of breath. She now has to stop to rest three or four times whenever she climbs the stairs to her apartment on the third floor. She reports chronic, nonproductive cough and wheezing, for which she uses ipratropium inhalers. She has a 25 pack-year smoking history. On examination, the blood pressure is 13080 mm Hg, the pulse rate is 95min, the temperature is 36.6C 97.8F, and the respiratory rate is 26min. Chest auscultation reveals bilateral crepitations. Cardiac auscultation reveals normal S1 and S2 without murmurs or added sounds. Arterial blood gas analysis shows:pH 7.36 reference: 7.357.45HCO3- 32 mEqL reference 2228 mEqLPco2 48 mm Hg reference: 3345 mm HgPo2 63 mm Hg reference: 75105 mm HgO2 saturation 91 reference: 9499Which of the following would you expect to find in this patient?? A: Decreased lung residual volume, B: Decreased diffusing capacity of the lungs for carbon monoxide DLCO, C: Increased FEV1FVC ratio, D: Shift of the flow volume loop to the right, E: Decreased lung compliance,  <response>: This is a patient with a 6-month history of progressive shortness of breath, chronic cough, wheezing, and smoking history. The description and findings are consistent with chronic obstructive pulmonary disease COPD. In COPD, there is airflow limitation that is not fully reversible. This would lead to decreased FEV1, FEV1FVC ratio, and diffusing capacity of the lungs. Lung volumes like residual volume are increased in COPD due to air trapping. The flow volume loop would be shifted down and to the left due to expiratory airflow limitation. Lung compliance is decreased in emphysema, a form of COPD, due to destruction of lung parenchyma.So the expected pulmonary function finding in this patient with COPD would be decreased FEV1FVC ratio.B: Decreased diffusing capacity of the lungs for carbon monoxide DLCO 