Question ID:PT77 S2 Q10 Passage:One year ago, a municipality banned dishwasher detergents containing phosphates. Anecdotal evidence indicates that many residents continued to use detergents containing phosphates; they just purchased them from out-of-town stores. However, it is clear that some residents did switch to phosphate-free detergents, since phosphate pollution from the municipal wastewater treatment plant decreased significantly in the past year. Stem:The answer to which one of the following questions would most help in evaluating the argument above? Correct Answer Choice:CChoice A:Why did many residents continue to use detergents containing phosphates? Choice B:What pollutants, if any, are present in phosphate-free dishwashing detergents? Choice C:Were any changes made in the past year to the way the municipality's wastewater treatment plant treats phosphates? Choice D:Does most of the phosphate pollution in the municipality's waterways come from treated wastewater from the municipal treatment plant? Choice E:Did municipal officials try to stop people from bringing detergents containing phosphates into the municipality?