问题如下：
If relative to prior values of their respective indicators, the inventory–sales ratio has risen, unit labor cost is stable, and real personal income has decreased, it is most likely that a peak in the business cycle:
选项：
A.has occurred.
B.is just about to occur.
C.will occur sometime into the future.
解释：
A is correct.
Both inventory–sales and unit labor costs are lagging indicators that decline somewhat after a peak. Real personal income is a coincident indicator that by its decline shows a slowdown in business activity.
考点： economic indicators
解析：库存销售比和单位劳动力成本都是滞后指标，在经济见顶后有所下降。实际个人收入是一个同步的指标，它的下降表明商业活动有所放缓。综上所述，经济已经见顶，面临下行压力。
为什么不能选B正在发生呢？ 之前有道题是说Inventory/Sale ratio 最高是在早期peak时，unit labor cost stable 不是也说明还没到recession吗？
