Interesting problem, Buhari. Out of curiosity, if you were to do this "in person," wouldn't you have the same problem? I am far from an expert on this, but it seems that you might need some kind of custom code.
Quiz
Force student to answer specific Questions out of many essay questions in a Quiz
Eztabaida hau blokeatu da eta beraz aurrerantzean ezingo duzu bertan erantzun.