A 50-year-old male smoker is evaluated for chronic shoness of breath. On physical examination his vital signs are: pulse 110 bpm; temperature normal; respirations 30/min with use of accessory muscles and pursed-lip breathing; blood pressure 110/78 mm Hg. Other peinent findings are: hea exam: apex beat (impulse) is medial to the midclavicular line with generalized decreased breath sounds on lung exam; ABGs (FiO2 0.21): pH 7.38; PCO2 47 mm Hg; PO2 67 mm Hg. PFTs/spirometry: FVC 2.80 L (67% of predicted); FEV1 1.56 (50% of predicted); FEV1/FVC% 56%; TLC 134% of predicted; RV 170% of predicted; DLCO 43% of predicted. There is no reversibility with bronchodilators. Chest radiograph are shown below.What is the most likely diagnosis?