Use your Words (Score 1)

Read these 2 sentences and find the error. I can't understand how people miss things like this. There's a rapidly-expanding section of the home electronics market which revolves around "devices". The reason for the parentheses is that it's difficult to know how to label these gadgets, because they don't fit easily into any pre-defined categories. For those of you who are a little slow or lack vocabulary, "" are not parentheses.