Your data tables are awful. You need one table for questions and another table for answers. Each entry in the answers table refers back to a question in the questions table and has a flag indicating whether it is the correct answer.
So, the QUESTIONS table has the following fields:
QUESTION_TYPE -- Like MC, TF, FIB ...
The ANSWERS table has the following fields:
Makes your life infinitely easier and obviates the raison d'etre for this question.