This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NVBDCP, NLEP, Subject name: Social & Preventive Medicine
Most efficient anti-larval measures to prevent urban malaria is: 
Select and explain. 
A. Clean drainage and sewerage systems, B. Cover overhead tanks properly, C. Filling cesspools and ditches, D. Cover pits
B: Cover overhead tanks properly
Answer: B: Cover overhead tanks properly 
Explanation: Recommended measures for urban malaria control: Lids of overhead tanks must be checked and maintained monthly basis; any leakage be repaired immediately. Cover-up of underground and open tanks. Open tanks used for animals should be dead dried once in week. Never throw any containers in open which are capable of holding water. Building by-laws be implemented to prevent fault in designs, water flow on roof, gully traps. Open tanks are treated with larvicides on weekly basis. Unused wells either be closed or treated with larvicides. Ornamental tanks, fountains are checked periodically & larvivorous fishes are introduced. Proper drainage, periodic flushing of water logged areas and drainage.