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: Surgery
Urobilinogen levels in obstructed jaundice due to gallstones will be: 
Select and explain. 
A. Markedly raised, B. Slightly increased, C. Normal, D. Completely absent
D: Completely absent
Answer: D: Completely absent 
Explanation: Ans: D. Completely absent(Ref: Harrison 19Ie p280, 18Ie p325)Suggestive of obstructive jaundice. Function testPrehepatic jaundiceHepatic jaundicePost-hepatic (Obstructive) jaundiceTotal bilirubinNormal/ increasedIncreaseddegIncreaseddegConjugated bilirubinNormalIncreaseddegIncreaseddegUnconjugated bilirubinNormal/ increasedIncreaseddegNormalUrobilinogenNormal/ increasedDecreaseddegDecreased/ negativedegUrine colorNormalDark (urobilinogen +conjugated bilirubin)degDark (conjugated bilirubin)degStool colorNormalNormal/paledegPaledegAlkaline phosphatase levelsNormalIncreaseddegIncreaseddegAlanine transferase & aspaate transferase levelsNormalIncreaseddegIncreaseddegConjugated bilirubin in urineAbsentdegPresentdegPresentdegSplenomegalyPresentdegPresentdegAbsentdeg