This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
[{'content': 'Type of dengue serotypes are ? \nSelect and explain. \nA. 2, B. 4, C. 5, D. 10', 'role': 'user'}, {'content': "Answer: B \nExplanation: -Dengue is caused by dengue virus. - there are four virus serotypes which we designated as DENV1, DENV2, DENV3 and DENV4. Reference: Park's textbook of preventive and social medicine, 23rd edition, pg no:247 <\\p>", 'role': 'assistant'}]