How does the​ labor-leisure trade-off determine the supply of​ labor? A. The supply of labor is no different than the supply of any other good or service in that it is primarily affected by production costs. In the case of​ labor, the dominant production cost is the cost incurred to acquire employable skills. The supply of labor is​ upward-sloping because higher wages are required to cover the expense of gaining more skills. B. An increase in the wage rate is an increase in the opportunity cost of​ leisure, and can therefore be expected to reduce the amount of leisure one wishes to consume. Choosing less leisure is equivalent to supplying more​ labor, thus yielding a positive relationship between the wage rate and the amount of labor supplied. C. Individuals typically trade off working versus leisure in an​ unplanned, unsystematic way. As a​ result, the supply of labor exhibits a bit of​ randomness, showing that higher wages sometimes increase the quantity of labor time supplied and sometimes decrease the quantity of labor time supplied. D. When an individual chooses an amount of leisure to​ consume, he is simultaneously choosing a quantity of labor to supply. Since leisure is a normal​ good, an increase in the wage induces more consumption of leisure and therefore a smaller quantity of labor supplied.