This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory, Subject name: Medicine
A previously well 53-year-old man develops progressive shortness of breath. Pulmonary function tests reveal a restrictive defect and a high-resolution CT suggests pulmonary fibrosis. Which of the following is the most likely role of transbronchial biopsy in this condition? 
Select and explain. 
A. assess disease severity, B. assess possible bronchiolar narrowing, C. diagnose specific causes of interstitial lung disease, D. determine degree of inflammation
C: diagnose specific causes of interstitial lung disease
Answer: C: diagnose specific causes of interstitial lung disease 
Explanation: Transbronchial biopsy helps differentiate idiopathic pulmonary fibrosis (IPF) from similar syndromes with specific treatments. These include chronic hypersensitivity pneumonitis, cryptogenic organizing pneumonia, and sarcoidosis.