Insecticide of choice to prevent kala-azar-: (A) DDT, (B) HCH, (C) Malathione, (D) Paris green
Answer is A. Ans. is 'a' i.e., DDT * Resistance to DDT has not been demonstrated in sandflies* A single application of DDT or lindane has been found effective in reducing sandflies.* DDT residue may remain effective for a period of 1 to 2 years and lindane only for a period of 3 months.