Deciding between "Always Resume" versus "Prompt to Resume"

Another potential "pro" for "Always Resume": If a course has limited attempts to pass the quiz, a user can't get more attempts by choosing to start the course over. 

You use the outline/menu, so someone could easily review previous content. Thus, I think "Always Resume" is a good option, because it saves a user from inadvertently being required to view everything again, but it doesn't restrict them from looking at the content again.