This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hereditary Hyperbilirubinemia & Jaundice, Subject name: Medicine
A patient presents with serum bilirubin values of >40mg% and obstructive jaundice. This indicates? 
Select and explain. 
A. Carcinoma of gallbladder, B. Concomitant renal failure, C. Acute cholecystitis, D. Complete obstruction of bile duct
B: Concomitant renal failure
Answer: B: Concomitant renal failure 
Explanation: In patients of obstructive jaundice the value of serum bilirubin plateaus around 25-30 mg% since the water soluble bilirubin is excreted the urine. However in concomitant renal failure, loss of conjugated bilirubin the kidney fails and leads to extremely high values. Another reason can be a simultaneous overproduction of unconjugated bilirubin due to haemolysis, sepsis and sickle cell anaemia.