This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Liver & Biliary Tract, Subject name: Pathology
[{'content': 'Absent urobilinogen in urine with icterus indicates? \nSelect and explain. \nA. Perihepatic obstruction, B. Hemolysis, C. Hepatitis, D. Liver failure', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Perihepatic obstruction(Ref: Robbins 9th/830-840; Harrisons 18th/chapter 42)ConditionSerum BilirubinUrine UrobilinogenUrine BilirubinFecal UrobilinogenNormalDirect 0.1-0.4 mg/dlIndirect 0.2-0.7 mg/dl0.4 mg/24 hAbsent40-280 mg/24hHemolytic anemia|IndirectIncreasedAbsentIncreasedHepatitis|Direct and indirectDecreased if micro obstruction is presentPresent if micro obstruction occursDecreasedObstructive jaundice| DirectAbsentPresentTrace to absent', 'role': 'assistant'}]