Quizzes report FP but do not report FN when multiple answers are valid

[rasbt]

Discussed in #17

^{Originally posted by agaldran January 16, 2023}
Just as the title shows, if a valid answer is not marked, this error will not be reported and we don't know we got it wrong, see below:

Above, the first option was also a valid answer, I did not mark it, but this was not repored as incorrect.

Thanks for the materials!

[rasbt]

Converted this to an issue to address this in the future. Will need some focus time with our web devs to tackle that.