Which method falls under the category of source reduction in mosquito control?

Source reduction in mosquito control refers to methods aimed at removing or managing potential habitats where mosquitoes breed. The correct answer, which involves eliminating standing water, directly targets the breeding grounds for mosquitoes. Mosquitoes lay their eggs in stagnant water, so by removing or reducing these water sources, the chances for mosquitoes to reproduce and proliferate significantly diminish. This proactive approach consequently reduces the population of adult mosquitoes over time.

In contrast, the other options provided do not focus on altering the physical environment to prevent mosquito breeding. Applying pesticides and using larvicides are methods that involve chemical applications to control mosquito populations, but they do not address the source of the problem by eliminating the breeding sites directly. Setting traps can help capture adult mosquitoes but does not impact the breeding cycle or prevent new mosquitoes from emerging. Therefore, eliminating standing water represents a fundamental preventive strategy in effective mosquito control practices.