问题如下：
The recession phase of a business cycle is most likely associated with:
选项：
A.high spending in industrial items.
B.high unemployment rate.
C.high aggregate economic activity.
解释：
B is correct.
During the contraction phase of a business cycle,the unemployment rate rises.
考点：Business Cycle Characteristics
解析：经济衰退时候，经济活跃度降低，所以C选项不入选
经济衰退，收益率降低，所以投资支出也会随之下降，A选项错误。
经济衰退时候就业机会减少，企业开始裁员，所以失业率会上升，B选项正确。
C选项是什么意思？
