Relational table deleting certain recrds

I have a list of question & 4 possible answer for each question.

These questions are asked to user depending upon Stage.
Basically its an application & application keep moving from one stage to another stage.
So lets say on "stage 1" i ask 10 question & next stage i ask 5 question. These are dynamic question which are asked depending upon stage of an application.

So Questions appear & on choosing answer it stored all of it. works fine til here.
Now when application stage is change to Stage2 or any other. then another set of question are asked. Note answer are stored with QuestionID, Answer & ApplicationID.

Questions appears depending upon stage of application. Stage 2 question when they are answered the stage 1 answer get deleted from db.

I m not able to understand why this is happening.