For all topics you start, there is basically [as per the site structure] an open question....so all of those will require that action to be done, if they actually have an anwer that is correct, then the appropriate action is to press the "Accept as solution" button. [see example image below]
This is ONLY an option for the person that began the post/thread.
In reference to the "Survey" [which I have also completed] the "tag line" at the bottom you refer to, for marking as an accepted solution, is on Susan's signature, when she originally posted it.
Design Manager Streetscape Limited
Solid Edge ST10 [MP1] Classic [x2 seats]
That's what Sean showed in his picture and it is only available for the person who created the first post.
So when you look at this thread, each message that Sean and I posted should have the button to mark our posts as an accepted solution.
That worked. I guess the threads I looked at for that were either not mine or were already checked as solved or something else was preventing that from showing up. I'm not sure, but every time I looked that option was not there including this thread before today. Not sure why.