A patient presents with breathless.He has bilateral basal repitations, lung function tests reveal decrease in total lung capacity and vital capacity (VC) with normal FEV1/VC ratio.The most likely disease is -

• A. Chronic bronchitis
• B. Idiopathic pulmonary fibrosis
• C. Cystic fibrosis
• D. Allergic bronchopulmonary aspergillosis