Answer:
D. It is never at zero.
Step-by-step explanation:
The unemployment rate is described as the percentage of the labor force that is jobless but actively seeking work. The labor force comprises an adult population that is currently working or seeking employment.
The unemployment rate is never at zero. At every moment, there is frictional unemployment as people switch jobs or new college graduates seeking their first job. There is also unemployment due to economic seasons. Even when the economy is considered to be at full employment, the unemployment level is not at zero but at around 3 to 5 percent.