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
All paicipate in Fatty acid synthesis except 
Select and explain. 
A. Hydratase, B. Reductase, C. Transacylase, D. Dehydrogenase
D: Dehydrogenase
Answer: D: Dehydrogenase 
Explanation: D i.e. Dehydrogenase