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
The contrast material used in the diagnosis of esophageal atresia is – 
Select and explain. 
A. Gastrograffin, B. Conray 420, C. Dianosil, D. Myodii
C: Dianosil
Answer: C: Dianosil 
Explanation: 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.