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': 'A dense renogram is obtained by – \nSelect and explain. \nA. Dehydrating the patient, B. Increasing the dose of contrast media, C. Rapid (Bolus) injection of dye, D. Using non–ionic media', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Rapid injection of dye is the preferred method for obtaining dense nephrogram.', 'role': 'assistant'}]