This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Contrast Agents, Subject name: Radiology
[{'content': 'Iodine paicle ratio for Ionic dimer is \nSelect and explain. \nA. 6:01, B. 3:02, C. 6:02, D. 2:06', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Iodine paicles ratio: I: P Ionic monomer 3: 2 High osmolar Low Osmolar Ionic dimer 6: 2 Nonionic monomer 3: 1 Low osmolar Non-ionic dimer 6: 1 Iso-osmolar to plasma(290-300mosm)', 'role': 'assistant'}]