最近复习gwd的时候再看讨论贴的时候碰到过几次“单独指代“
的问题，以前对这个概念从来没有听说过，请各位帮助解答一下，我查找了没有找到相关内容，现特举一例：
GWD-8-Q32:
At the annual stockholders meeting, investors heard a presentation on the numerous challenges facing the company, including among them the threat from a rival’s multibillion-dollar patent-infringement suit and the declining sales for the company’s powerful microprocessor chip.
A. including among them the threat from a rival’s multibillion-dollar patentinfringement suit and the declining sales for
B. which includes the threat of a rival’s multibillion-dollar patent-infringement suit and declining sales of
C. included among these the threat from a rival’s multibillion-dollar patentinfringement suit as well as a decline in sales for
D. among them the threat of a rival’s multibillion-dollar patent-infringement suit and the decline in sales of
E. among these the threat from a rival’s multibillion-dollar patent-infringement suit as well as the decline in sales for
CAE，these不能单独指代，这是指的什么意思啊？在这里怎么对them和these进行选择？
不明白，求讲解！谢谢 | 
