The energy-efficient washer and dryer set costs $3,180, has a 12 year life and incurs an average $210 cost per year in the electricity consumption. The regular washer and dryer set costs $1,980, has a 8 year life and incurs $320 cost per year in the electricity consumption. Given the rate of return is 8%, Which washer and dryer set would you recommend to purchase and why? Select one: a. The energy-efficient set because its equivalent annual cost is lower than the regular set. b. The regular set because its equivalent annual cost is lower than the energy-efficient set . c. The regular set because its NPV is less negative. d. The energy efficient set because its NPV is less negative. e. Cannot be determined because the two sets of washer and dryer have different life span