Opportunity cost is

A.not relevant for macroeconomic decisions but is the main consideration in microeconomic decisions
B. The value of the best alternative that must be given up when a choice is made
C. Maximized when the benefits of an activity outweigh the costs of an activity
D.higher for labor resources than for capital resources

B. The value of the best alternative that must be given up when a choice is made

B. The value of the best alternative that must be given up when a choice is made