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
Which of the following is not a phase I reaction - 
Select and explain. 
A. Oxidation, B. Reduction, C. Hydrolysis, D. Conjugation
D: Conjugation
Answer: D: Conjugation 
Explanation: Phase I reactions →  Oxidation (including hydroxylation), reduction, hydrolysis, cyclization and decyclization.
Phase II reactions → Conjugation reaction (glucuronidation, sulfation, acetylation, methylation, conjugation with glutathione, aminoacid conjugation).