When asking a guard for directions, some of the features the original wow game has is not included in the storyline addon as you can see below. I had to remove the add on to simply be able to find trainers :(

You can use the mouse wheel on the selection list to scroll the list.

We should add a tutorial popup that is shown the first time the user is in this situation to tell them they can scroll using the scroll wheel.

Also related issue #4 to add an option to show the scrollbar (currently here and interactive, but not visible)

Version 3.1.2 introduced tutorials to inform users that they can scroll on the list when more options are available.