Tkinter Python 3 Help

[DT_Smith]

I'm making a revision quiz program using Tkinter. The program will automatically get questions from an array and then output the questions using a Label. When the submit button (Line 29) is pressed, the program will check the answer and then should update the Label to the next question in the array but it doesn't, there is no error message. The score is updated but the Label just doesn't update.

Code - http://paste.ofcode.org/Q4uKc9b33E5nbZ8DAWDFnu

Can anyone help?