6. In the averting expenditures model shown below, if environmental quality is 61, and personal environmental quality is X1, the area or distance that represents the individual's averting expenditures is MCy based on overall environmental quality Er "MCz based on overall environmental quality Ez MB Personal environmental quality (x) A. edfX1 B. edhX2 C. deb D. edfhXz 7. Installing an air purifier or a water filtration system is an example of a(n) A. direct estimation method B. ozone-reducing policy C. physical linkage approach D. averting action