This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
[{'content': 'A 2 month baby presents with history of jaundice, turmeric colored urine and pale stools since bih. Examination reveals liver span of 10 cms, firm in consistency and spleen of 3 cms. The most specific investigation for establishing the diagnosis would be: \nSelect and explain. \nA. Liver function tests, B. Ultrasound abdomen, C. Peroperative cholangiogram, D. Liver biopsy', 'role': 'user'}, {'content': 'Answer: C \nExplanation: All patients suspected of having biliary atresia should undergo exploratory laprotomy and direct cholangiography to determine the presence and site of obstruction. Ref: Kliegman, Behrman, Jenson, Stanton (2008), Chapter 353, "Cholestasis", In the book, "NELSON TEXTBOOK OF PEDIATRICS", Volume 2, 18th Edition, New Delhi, Page 1673; Harrison\'s Internal Medicine, 18th Edition, Page 2624.', 'role': 'assistant'}]