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': 'The contrast material used in the diagnosis of esophageal atresia is – \nSelect and explain. \nA. Gastrograffin, B. Conray 420, C. Dianosil, D. Myodii', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Dianosil is used in oesophageal atresia, as in most cases it is frequently associated with tracheo-oesophageal fistula; so on instillation of contrast media, there is a risk of flooding in the lungs.', 'role': 'assistant'}]