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: Radiology
[{'content': 'To obtain better information of a cyst eroding the surface of cortex \nSelect and explain. \nA. Exposure time should be reduced, B. Exposure time should be increased, C. Voltage should be increased, D. Milliamperage increased', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]