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: Biochemistry
Bilirubin is absent in urine because it is - 
Select and explain. 
A. Distributed in the body fat, B. Conjugated with glucoronide, C. Not filterable, D. Lipophilic
D: Lipophilic
Answer: D: Lipophilic 
Explanation: Unconjugated bilirubin cannot be excreted in urine because:-

(i) It is lipophilic (lipid soluble) but not water soluble, i.e. it is hydrophobic 
(ii) It is tightly bound to albumin, thus cannot be filtered at glomeruli.