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': 'Which of the following procedures is used as a routine technique in karyotyping using light microscopy? \nSelect and explain. \nA. G banding, B. C banding, C. Q banding, D. Brd V-staining', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]