The following steps are a useful way to ensure that a Learner completes a quiz/assessment without exiting the topic. 

** This example presumes that the Quiz topic is the final topic in your project

1. Go into the Configure settings for each question screen you can disable the Back arrow by un-ticking the highlighted field. This will force the learner to continue through the quiz screens until the end
2. If you have a Menu Navigation button on your project then this can also be disabled for each screen. This will prevent the learner from exiting the quiz topic to return to the Menu

3. If you have an Assessment Results screen at the end of the quiz then you can do the same for that screen
This should mean that the only option available to the Leaner will be to exit the course on completion of the quiz