Remove Individual Question Separators

Hi there. I'm wondering if there's a way to remove the question separator line between two specific questions (not from the entire survey).
The reason I ask is because there's still no option to add a 'comments about your answer' after a multiple choice question. There are two options consistently offered in these forums: a) Using an extra choice with text enty forces the question to be non-exclusive (bad); and b) making the 'comments about your answer' a separate text box question after the multiple choice question. The problem with option B is that then it looks like a separate question, which messes with the user's flow. So I'm wondering if there's a way to use custom css to tell the survey not to show the question separator after question / before question y.
(And this post can be considered another person voting for an option to collect comments after multiple choice questions, it's such a common need.)
Thanks!