I've done a bit of cleanup on Template:Quiz_Multiple_Choice (and the underlying Widget:Quiz_Multiple_Choice). I've also updated the documentation and added TemplateData for the benefit of users of the experimental VisualEditor.
The most user visible changes:
1. The template is now a proper assessment iDevice (and among other things, accepts a "theme" parameter).
2. Positional/numeric template parameters are now deprecated. All new work should use the "body" (and "title") parameters. The old first parameter that was a unique string identifying the quiz on the page is no longer used.
3. The "hint" is always shown (rather than being behind a disclosure link). This is a current limitation of the iDevice template, and will probably be corrected.
If there are not too many howls of protest, expect similar changes to Template:Quiz_Cloze.