This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Interstitial Lung Disease, Subject name: Medicine
What is the investigation of choice for interstitial lung disease? 
Select and explain. 
A. Chest X-ray, B. HRCT, C. Gallium - 67 DTPA scan, D. MRI
B: HRCT
Answer: B: HRCT 
Explanation: Ideally lung biopsy should be done but is not given in the choices. High-resolution computed tomography is superior to the plain chest x-ray for early detection and confirmation of suspected ILD. In addition, HRCT allows better assessment of the extent and distribution of disease. In the appropriate clinical setting HRCT may be sufficiently characteristic to preclude the need for lung biopsy.