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: Microbiology
[{'content': 'Diagnosis of rotavirus is by: \nSelect and explain. \nA. Stool antigen, B. Stool antibody, C. Stool culture, D. Blood antibody', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. d. Blood antibody', 'role': 'assistant'}]