单选题 All of the following are factors that can cause shifts in the demand curve for a resource EXCEPT:

A. an increase in the supply of the resource.
B. an increase in the resource's productivity.
C. a decrease in the prices of other resources.

【正确答案】 A

【答案解析】There is no reason to believe that an increased supply will cause a shift in the demand curve. There is no indication to whether a supplier will reduce the price to reflect the change in supply.