This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of protein and amino acid, Subject name: Biochemistry
[{'content': 'Which of the following amino acids is purely ketogenic? \nSelect and explain. \nA. Phenylalanine, B. Leucine, C. Proline, D. Tyrosine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Purely ketogenic amino acid is LeucineRef: Textbook of biochemistry for medical students, seventh edition, page no: 27', 'role': 'assistant'}]