问题如下：
Projecting profit margins into the future on the basis of past results would be most reliable when the company:
选项：
A.is in the commodities business.
B.operates in a single business segment.
C.is a large, diversified company operating in mature industries.
解释：
For a large, diversified company, margin changes in different business segments may offset each other. Furthermore, margins are most likely to be stable in mature industries.
diversify 是不是也理解为多元化的意思，一个单一行业经营的企业 应该比多元化企业更适合历史预测吧？
