想问一下，B选项为什么错误？另外这里的答案解析，中文解析有误。

问题如下：

The full employment, or natural, level of output is best described as:

选项：

A.the maximum level obtainable with existing resources. B.the level at which all available workers have jobs consistent with their skills. C.a level with a modest, stable pool of unemployed workers transitioning to new jobs.

解释：

At the full employment, or natural, level of output the economy is operating at an efficient and unconstrained level of production. Companies have enough spare capacity to avoid bottlenecks, and there is a modest, stable pool of unemployed workers (job seekers equal job vacancies) looking for and transitioning into new jobs.

中文解析：

对于给定的劳动年龄人口，劳动力参与率的下降(通常是由于气馁的工人增加造成的)减少了劳动力。如果就业人数保持不变，而劳动力数量减少，那么被定义为失业的工人数量一定会减少，从而失业率会降低。