6. Which of the following would be an effective means of benchmarking? a. Comparing a city's key ratios to those of special purpose governments in the area. b. Comparing current-period ratios to published medians of the same ra- tios for cities of similar size or in the same geographic region. c. Comparing key ratios to published medians of the same ratios for larger cities in other parts of the country. d. Comparing current-period ratios to estimates for future periods.