问题如下：
Which is the main difference between cyclical and non-cyclical firms?
选项：
A.Their stock price suffer market condition influence.
B.Earnings of cyclical firms are highly dependent on the stage of the business cycle.
C.Earnings of the cyclical firms fluctuate within the same peer group.
解释：
B is correct.
Earnings of cyclical firms are sensitive to the stage of the business cycle, and non-cyclical firms are relatively stable over the business cycle.
老师，我对选B有点不理解，这题说的是周期型和非周期公司的区别吧，我理解是不是应该行业的周期，行业的起起落落吧，business cycle是不是指这个公司的成长阶段？
