If I understand correctly, your Parse JSON module gives you the array of collections shown in your text window. Each element in that array is a collection consisting of “text” (the question) and “answers” (an array of multiple choice answers).
You’re not just trying to pick array element at random - that might result in the same element being picked again. You need to produce an entirely new array that has been shuffled. You need to shuffle both the top level array, and within each of those top levels, you need to shuffle the answers.
Make includes a handy “shuffle” function in the array functions. Shuffle() returns a new, shuffled array.
So I would use the Iterator to turn your top-level array into bundles. For each of these bundles you would then construct a new data structure of the “text” and a shuffled array for the answers. You’d then use the Aggregator to turn all those back into a top-level array, and then you’d shuffle that.
The downside is that this could use a lot of operations. If you had say 3 operations, you’ll use 3 x Q x A operations (where Q = number of questions and A = number of answers).