I believe this is a type of compound interest problem. I am still unable to solve this. Please help me. Thanks

You must choose between four pieces of comparable equipment based on the cash flows given below. All four pieces have a life of 8 years. Parameter Equipment $25,000$35,000 $20,000 $40,000 Annual costs $8,000 6,000 $9,000 $5,000 Salvage value $2,500$3,500 $2,000 $4,000 First cost The discount rate is 12%. Ignore taxes. The most preferable top two projects and the difference between their present worth values are most nearly: (A) (B) (C) (D) A and C, $170 B and D, $170 A and C, $234 B and D, $234