How to prevent granting Userpoints again after a user already passed a Quiz? I'm using the Quiz and the User Points module.

After a user takes a quiz, the points are granted. But if the quiz is taken multiple times, the points are granted multiple times also. For example;


points balance: 0
after quiz (1st time), point balance: 10
take the same quiz again, point balance becomes: 10+10=20


I don't want it to be cumulative. How can I prevent this?
You might use the Rules module to take away the role which has the permission to take the quiz once the quiz has been completed.