GWD 22 32,句子之间居然没有连接词！！困惑

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.

1. including among them the threat from a rival’s multibillion-dollar patent-infringement suit and the declining sales for

2. which includes the threat of a rival’s multibillion-dollar patent-infringement suit and declining sales of

3. included among these the threat from a rival’s multibillion-dollar patent-infringement suit as well as a decline in sales for

4. among them the threat of a rival’s multibillion-dollar patent-infringement suit and the decline in sales of
5. among these the threat from a rival’s multibillion-dollar patent-infringement suit as well as the decline in sales for

答案选D，但是逗号后面不是应该有连接词吗？