What is one mechanism that has been proposed to explain the longer life associated with optimism?

What is the best way to use the clean water act to address the issue of dirty water and diseases that plague asmall community? a) to report the number of cases of people who havecholera symptomsb) to provide health guidelines about effects from waterborne diseases c) to enforce standards that focus on chemical dischargeinto bodies of waterd) to carry out research that investigates how dirty wateraffects human health