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': 'The Iodine:Paicle ratio is maximum for \nSelect and explain. \nA. Ionic monomers, B. Ionic dimers, C. Non-ionic dimers, D. Non-ionic monomers', 'role': 'user'}, {'content': 'Answer: C \nExplanation: -Iodine Paicle Ratio of Ionic Monomer - 3:2 - Ratio of Ionic Dimer - 6:2 - Ratio of Non-ionic Monomer - 3:1 - Ratio for Non-ionic Dimer is - 6:1', 'role': 'assistant'}]