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
UDP-Glucose is converted to UDP galactose by 
Select and explain. 
A. lactose synthetase, B. Epimerase, C. Pyruvate kinase, D. all of the above
B: Epimerase
Answer: B: Epimerase 
Explanation: None