A good is scarce if we must sacrifice something to obtain it.

The opportunity cost of an action is equal to: a. only the monetary payment the action required

b. the total time spent by all parties in carrying out the action. c. the highest valued opportunity that must be sacrificed in order to take the action. d. the value of all of the alternative actions that could have been taken.

Evidence points out that since the mid-1950's just about every recession was preceded by rising interest rates. This suggests that the recessions were:

A. caused by simultaneous shifts in aggregate demand and aggregate supply. B. due to increases in oil prices and other production costs. C. the result of changes in consumer confidence. D. caused in part by the actions of the Federal Reserve.