Social & Preventive Medicine If API>2, the vector is resistant to DDT, the malathion spray should be done every A 3 round of malathion every 3 months B 2 round or malathion every months C 1 -2 round of malathion every 3 months D One round of malathion every month 💡 Explanation If API>2, the vector is resistant to DDT, the malathion spray should be done every ✓ Correct Answer: A. 3 round of malathion every 3 months