Hi, Erin. You are right about what the Pick 3 a option will do: it serves up a random 3 out of 4 questions.

If it were me, I would accomplish your goal by using the "text (no question)" option on a question:

Use that to present all of your options, and then follow that with three essay questions that say something like: Pick one of the topics presented above to answer this questions with a well-developed paragraph . . . "   -- or something like that.

Do you think that would work for you?