Quiz Help

iam making like a simple quiz program using C# windows application


i made 4 check boxes each check box have it's own answer

and a label which show up the question

and a progress bar

i got 2 problems

when check box more than once it keep at progress to the bar

i need it to add it once

and other problem

wanna change question whenever any box checked

i made it like this

but when tried to repeat that code again to be
it gives the main question + New Question again and it skip New Question