If you like the way that the printout of the entire page looks, but you want only one answer to print, try this:
In Firefox on Windows:
Open the menu item Tools > Web Developer > Style Editor. (The style editor is part of the "inspector" and there are a couple of ways to get to it.)
This is the CSS for the page. Add, somewhere outside of any other block (I went to the end), two lines like these:
.question, .answer { display:none; }
#answer-80449 { display: block; }
When you add the first line, all the questions and answers (which live within HTML containers like <div class="question">
etc.) will disappear; when you add the second, any code contained in <div id="answer-XXX">
will reappear. The phone number is the post ID, which you can extract from the "share" link (or confirm by viewing the source).
Your printed view should match what's on the screen.
Now my Firefox seems to be having this problem, but since the answer in your example fits on a single page I haven't attempted to fix it.
I'm sure this feature is available in other browsers. The tricky part is figuring out where to add the CSS; the code that you add should be the same.
I see in your comments that you're probably not thrilled about this sort of "clunky interface," but this is the sort of thing that's probably pretty easy for someone to turn into a browser extension.