A patient has been a coal miner for fifty years and has shortness of breath, a diminished FEV1 and TLC on pulmonary function testing and has hypoxemia by pulse oximetry. What is the likely diagnosis?
a) Hypersensitivity pneumonitis
b) Idiopathic pulmonary fibrosis
c) Pneumoconiosis
d) Primary spontaneous pneumothorax (PSP)