Create a "decline to respond" option?

[jarvis24]

My advisor and I want to use horizontal scaled response items with a "decline to answer" option. The simplest way to do this, of course, is to simply have an option labeled "decline to answer." But the thing is, we'd like that option to be set apart from the other options in such a way that it won't appear to the participants like its part of the scale. We've wondered if there was a way to do this by, perhaps, physically distancing it from the scale, or by inserting a line between it and the scale.
Is there a solution to this problem?