Event handler for group radio button

Question

Hello

I am developing a multiple choice quiz application

Each question has four options to choose from by the user.

My questions are

-how can i set eventhandler for the radio buttons to make the user know if the option choosen is right or wrong

-I dont want the user to know the right or wrong answer untill they finish the quiz

-I want the event handler to also show the numbers of right and wrong answers with total score of the user at the end of the quiz

Regards