We need an advanced option in QA that will prevent students from redoing the question once they submit their answers.

The current runtime workflow for Q&A is:

1) Student submits answer
2) Student gets a page to confirm his answer -see the teacher's feedback if it was included at authoring time (with an option to redo if needed)
3) If student accepts, he/she sees his answer and everyone else's too (if that option is on -which is the case by default).

These new advance option feature will change this slightly:

1) Student submits answer
2) Student gets a page to confirm his answer -see the teacher's feedback if it was included at authoring time, but does *not* get the option for redo
3) If student accepts, he/she sees his answer and everyone else's too (if that option is on -which is the case by default) and as this feature is on, the option for "Locked when finished" should be default to ON too.

So summarizing, when this option is ON, then the student gets no option to redo a question and the locked when finished is also ON.