watch video before answering question

Hello John and thank you very much for your post!

The honest answer is that I think there's no way to guarantee that, at least not without customizing the video player events somehow.
Do you think that they will skip the videos? Is that a problem if the student already knows the answer? I'm just asking to better understand your question.

Thanks again.

I understand.
Here's what I have to propose.
1. Maybe you can find a video player that triggers some Javascript events, especially when the video is completed. If we had such a video player (you may also ask AllVideos if it does that) we could possibly implement something to only allow the quiz-taker to proceed after the video has completed. However, I believe that even if we had that, a user could simply drag the video slider near the end of the video and then skip to the next question.
2. Another possible solution would be to require a certain amount of time before the quiz-taker can proceed to the next question. However, that could become very annoying and quiz-takers may be discouraged from staying and finishing the test.

Either way, it becomes sort of vague. One third solution I'm thinking of, would be to somehow make the video modal. (appear in the middle of the screen without the option to be removed before it ends)
Something like the interstitial ads we see in applications. I currently don't have any ideas on how to implement it on a website, though.

I'm glad to have somehow helped.
Let me know if anything of these works for you, and feel free to ask if there's anything else I can do to help.