Except for the question, the options, and the answers, they are all related.
I would like to get it to work using a dictionary, whereby a screen will be used for all subjects.
Here is what I could come up with: I am stuck!
Since you can only display one subject at a time, you should only need one screen shared by all subjects (possibly a virtual screen). It would not necessarily require a dictionary, using a List might be easier and the information could be stored in text files - that way, it would be possible to add new subjects by just producing a new text file and not having to edit, recompile and redistribute the App.
There are a number of Quiz App examples in the Gallery, I suggest you peruse those.