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
The conjugation of bilirubin to glucuronic acid in the liver - 
Select and explain. 
A. Converts a hydrophilic compound to a hydrophobic one, B. Converts a hydrophobic compound to a hydrophilic one, C. Enables the bilirubin molecule to cross the cell membrane, D. Is increased during neonatal jaundice
B: Converts a hydrophobic compound to a hydrophilic one
Answer: B: Converts a hydrophobic compound to a hydrophilic one 
Explanation: Unconjugated bilirubin (hydrophobic) is converted to conjugated bilirubin (hydrophilic) by the process of conjugation with UDP-glucuronic acid in the liver.
As conjugated bilirubin is hydrophilic (not lipophilic) it cannot cross the plasma membrane easily (lipophilic or lipid soluble substances cross plasma membrane easily). Thus, unconjugated bilirubin (lipophilic) can cross plasma membrane easily but not conjugated bilirubin (hydrophilic).
In neonatal jaundice, conjugation process is immature.