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: Medicine
[{'content': 'Antigen antiboey reaction is detected by: \nSelect and explain. \nA. ELISA, B. Southern blot, C. Nohern blot, D. All', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. ELISA', 'role': 'assistant'}]