3) Array seems to be good for the first quiz but not for the updating or reusing the app with other questions and answers. If for you it's programmatically possible load the values(questions/answers) with the AJAX-Plugin or maybe with the load JSON Plugin
from a external textfile.
pro: Think once and make hundreds of quizzes all with different questions and answers.
with luck the load JSON plugin fits to your wishes - then there should be no con.