As oil prices increase, it becomes more economical to extract oil from sources like tar sands

After the price of smartphone apps falls, Justin buys fewer flash drives but he buys a new smartphone. For Justin

A) smartphone apps and flash drives are complements, and smartphone apps and smartphones are substitutes. B) smartphone apps, flash drives, and smartphones are all complements. C) smartphone apps and flash drives are substitutes, and smartphone apps and smartphones are complements. D) smartphone apps, flash drives, and smartphones are not all complements.

Goods that are rival in consumption and excludable would be considered

a. club goods. b. common resources. c. public goods. d. private goods.