Random form load c#

I have a short quiz of 4 questions, each question is on a different form (Quiz1, Quiz2 etc). I want to randomly load a form depending if it has been answered or not. I have two AnsweredQuestions and UnansweredQuestions.

Using static Random rnd = new Random(); and int r = rnd.Next(list.Count);

can I pick a number from the list then use a switch to load the next form?

or is there an easier/shorter option?

ps. I had a look at other answers here and tried to come up with my own solution but im having some trouble. Thanks guys.