I would like to suggest a feature (fi it doesn't already exist)
User is awarded 10 points for passing a quiz on response #1
5 points for response #2
1 point for response #3
0 points for response #4 to whatever
I like to the option to where the user is allowed multiple responses but i don't want to award them any points for retaking the same quiz over and over.
Then, i would suggest the option to turn off multiple responses, only if the user passes the quiz.