[讨论][求助]GWD-8-Q32 一个有意思的结构

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

正确的是D

这个句子结构到底是怎样的呢？ 独立主格？倒装？？

请搞人指教 谢谢

among them = including