What cost should consumers take into consideration when making more economically and environmentally conscious appliance purchases? 

A)  the operating cost 
B)  the life cycle cost 
C)  the external cost 
D)  the initial cost

Consumers should take into consideration the life cycle cost of the appliance, which includes not only the initial cost but also the operating cost, maintenance cost, and disposal cost. This will help them make more economically and environmentally conscious appliance purchases in the long run. The external cost, which refers to the cost imposed on society or the environment, should also be considered, but it is often difficult to quantify and may not be readily available to consumers.