6) The Consolidated Oil Company must install antipollution equipment in a new refinery to meet federal clean-air standards. Four design alternatives are being considered, which will have capital investment and annual operating expenses as shown below. Assuming a useful life of 10 years for each design, no market value, a desired MARR of 11% per year, determine which design should be selected on the basis of the PW, FW and AW methods. (30 p.) Design Capital Investment Annual Expenses DI $600,000 $780,000 D2 $760,000 $746,000 $1,240,000 $680,000 D4 $1,600,000 $574,000 D3