这是答案的解释： For a given working-age population, a decline in the labor force participation rate, oftern due to an increase in discouraged workers, reduces the labor force. If the number of people employed remains the same while the labor force is smaller, the number of workers defined to be unemployed must be smaller and the unemployment rate lower。

题目是：Holding the working-age population constant, if the labor force participation rate declines while the number of people employed remains unchanged ,the unemployment is most likely to :
A increase
B decrease

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