This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Plague, Subject name: Social & Preventive Medicine
[{'content': 'Plague is transmitted by all EXCEPT? \nSelect and explain. \nA. X. Cheopsis, B. X. Astia, C. Pulexirritans, D. Culex', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. (d) CulexRef : K. Park 23rd ed. / 292-93* The commonest and most effective vector of plague is rat flea x.cheopsis.* Others are X.Astia, X.Brasiliensis and Pulexirritans.* Culex is a vector of lymphatic filariasis and Japanese encephalitis (culex tritaeniorhynchus).', 'role': 'assistant'}]