This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins and Amino Acids, Subject name: Biochemistry
[{'content': 'Urea is formed in: \nSelect and explain. \nA. Brain, B. Kidney, C. Liver, D. Intestine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C & A Harper, 26th ed, p. 244 & 25,h ed, p. 319', 'role': 'assistant'}]