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': 'Allergic reactions to radiological contrast agents are - \nSelect and explain. \nA. Anaphylactic reactions, B. IgE mediated reactions, C. Urticaria, D. Edema', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Acute non-renal reaction to a radiocontrast agent may be -\n\n\nNon-IgE mediated anaphylactic reactions\nVasomotor / vasovagal reactions.', 'role': 'assistant'}]