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': 'First complication after radiotherapy is: \nSelect and explain. \nA. Mucositis, B. Candidiasis, C. Alopecia, D. Xerostomia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]