how to ask randomized follow up questions

I have a block with 2 questions, each has 20 options (40 in total). The participants are allowed to pick one option at a time. If they pick an option (let's say option A) another page will open to give them more details about option A. Then, they are asked if they want to read more options. In case their answer is yes, then they go to the block with 40 options and they can pick another option. I have put all the 40 explanations in a separate block. So, it is a loop between two blocks. I made 40 loops of if they want to read more show them the "List of snippets" block and then show them the "explanation" block and if they want to read more the same story. Since, I want to save all the options they have picked. Therefore, I used embedded data as you see. ! Now, I need to ask them some follow up questions regarding their selections. I need to ask the questions after they're done with the reading task. So, I don't want to ask the questions right after the explanations. I need to ask them related questions though. It means if they have picked 10 options from question 1, and 8 options from question 2. I need to ask them 5 (10/2) randomized follow up questions out of those 10 selected options in the question 1 and 4 randomized follow up questions out of those 8 selected options in question 2 . How can I do that?