Thank you for the answers
It's not so important to use C for this. We can also do it with Python. Things we need to make is: we want to use the display only to show our questions of the quiz with the answers and a countdown of 10 seconds where you have time to choose your answer. We have made controllers. These controllers are telling the answers of the people to another device, we learnt programmig with. The Raspberry tells the correct answer to the other programming device (only used in Switzerland for education, i think).
Thank you for your attention