Which of the following cost curves always declines continuously as output increases?

Wages for some workers do fall during a recession, but it is often:

A. too small of a wage decrease to contribute to economic recovery. B. only after the worker's current contract expires. C. only after the worker receives an annual performance evaluation. D. only after the worker is fired and gets rehired elsewhere at a lower wage.

Economics is the study of how

A) people make money. B) preferences are determined. C) psychology influences preferences. D) people make choices.