This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Environment and health, Subject name: Social & Preventive Medicine
[{'content': 'Which one of the following is a stomach poison for the larvae of insects of medical impoance? \nSelect and explain. \nA. DDT, B. Paris green, C. Pyrethrum, D. Antilarva oil', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Insecticides are substances used to kill insects.They are contact poisons,stomach poisons,fumigants. Stomach poisons are those which when ingested cause death of the insects. Examples are paris green and sodium flouride. DDT and pyrethrum are synthetic and natural contact poisons respectively. Parks textbook of preventive and social medicine.K Park. Edition 23.Pg no: 783', 'role': 'assistant'}]