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: Pathology
What is/are true about bilirubin? 
Select and explain. 
A. Conjugation is rate limiting step, B. Bilirubin has affinity for elastin, C. Conjugated bilirubin is maximum in blood, D. All
B: Bilirubin has affinity for elastin
Answer: B: Bilirubin has affinity for elastin 
Explanation: Ans. is 'b' i.e., Bilirubin has affinity for elastino Excretion of conjugated bilirubin into biliary canaliculi is the rate limiting step in bilirubin metabolism o Bilirubin has affinity for elastin, therefore jaundice is most easily seen in the sclera.o Normally unconjugated bilirubin is more than conjugated bilirubin, in bloodTotal bilirubin 0.3 -- 1.9 mg/dlConjugated bilirubin --> 0 to 0.3 mg/dlUnconjugated bilirubin --> Total - conjugated (0.3 -- 1.6 mg/dl)o Normally hemoglobin content of blood is between 120-160 gm/L (Harrison 17th/e p. A-2), and a normal adult usually have 5 litre of blood. So total hemoglobin is 600-800 gm.