GMAT Sentence Correction (SC) | Re: At the annual stockholders meeting, investors heard a

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 patent-infringement suit and the declining salesfor [color=#fff200]WE CANT USE PARTICIPLE MODIFIERS WITH COMMA[/color]