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: Pathology
[{'content': 'Retinoblastoma gene is located on chromosome ? \nSelect and explain. \nA. 6, B. 9, C. 13, D. 21', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., 13", 'role': 'assistant'}]