Final answer:
Efficiency wages, minimum-wage laws, and unions keep wages below the equilibrium level, causing a surplus of labor. Therefore, the correct option is B.
Step-by-step explanation:
The correct answer is b. below the equilibrium level, causing a surplus of labor.
Efficiency wages, minimum-wage laws, and unions can all result in wages being set above the equilibrium level, creating a surplus of labor.
Efficiency wages are higher wages paid by firms to increase worker productivity and reduce turnover. Minimum-wage laws set a floor on wages, which can lead to a surplus of labor if the minimum wage is set above the equilibrium wage. Unions negotiate higher wages for their members, which can also result in a surplus of labor.