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': 'The phenomenon of genetic reassortment - \nSelect and explain. \nA. Can occur during reovirus replication, B. Involves the crossing over of genes within an RNA segment, C. Can occur during influenza virus replication, D. Can occur only with RNA viruses of plus polarity', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]