This is a simple shuffle procedure:
But you don't want to shuffle only the questions, since the answers have to be in the same position in the list as their questions.
So instead, you build a list of the number from 1 up to 4 (the number of questions you have, and shuffle the list of question numbers.
Then you follow the contents of the list, using the items to look up the next question and answer as you administer the quiz.