For the 18th Amendment, we can probably mostly agree on what happened. But it only works because the wrong answers are very obviously wrong (and virtually impossible). But that forces you into answering along the path which is clearly not as wrong, even though it's full of vague sweeping generalizations. There were many small time bootleggers, for instance. I think it's a crummy idea to reduce history this way - who are you trying to teach a lesson, and why should someone trust that your interpretation of the chain of events is accurate?