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: Unknown
[{'content': 'All are true regarding DDT, EXCEPT: \nSelect and explain. \nA. It acts as neurotoxin, B. It is primarily a contact poison, C. It does not cause immediate death, but it takes several hours to kill, D. It has repellent action on insects', 'role': 'user'}, {'content': 'Answer: D \nExplanation: DDT (Dichloro diphenyl trichloroethane)\n♦It was first synthesized in by a German chemist, Ziedler.\n♦Its insecticidal action was described by Paul Muller.\n♦It is primarily a contact poison.\n♦It acts on nervous system of insects.\n♦It takes several hours to kill the insect.\n♦The residual action of DDT may last as long as 18 months.\n♦It has no repellent action on insects.\n♦As a residual spray, DDT is applied at a dosage of 100–200 mg/ sq. foot area.\n♦The formulation of choice is a 5 % suspension, 5–10 % strength for the control of lice, fleas, ticks, and bugs.', 'role': 'assistant'}]