可以详细讲一讲A和C的区别吗

问题如下：

By studying the Dow Jones Index and correlation levels of stocks from 1972 to 2012, the following empirical conclusions can be drawn:

选项：

A.

Correlation levels are lowest in strong economic growth times and correlation levels typically increase in recessions.

B.

Correlation levels are lowest in normal periods and correlation levels typically increase in recessions.

C.

Correlation levels are lowest in recessions and correlation levels typically increase in strong economic growth times.

D.

Correlation levels are lowest in normal periods and correlation levels typically increase in strong economic growth times.

解释：

A is correct.

考点：实证结论

解析：在强劲的经济增长时期，相关性水平最低，而在衰退中相关性水平通常会增加。