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
Urea synthesis is mediated by 
Select and explain. 
A. Ornithine decarboxylase, B. Aspartate transaminase, C. Arginase, D. Citrulline synthase
C: Arginase
Answer: C: Arginase 
Explanation: Arginase catalyses the formation of urea from arginine.