How to make Row() formula dynamic based on a cell content?

I am creating a multiple choice (see column A) and I want it to be randomized (see column C). I saw a formula in the internet, modified it, and it really does randomized the contents of each cell in column A. But one problem is that, the number of multiple choice options vary. For example, in row 2 I only have 3 options; in row 3 I have 4 options; in row 4 I have 5 options. The problem is, in order for the formula to work, the range (see the highlighted yellow part of the formula) must also coincide the number of options. I have tried my best but I'm really stuck on this. I can't find a way to make it dynamic based on the number of multiple choice options. Can you help me with this? Thank you so much!Here's the link to my Google Sheet https://docs.google.com/spreadsheets/d/1RnN7CUiuFt6m2q6ii3B6pEG9kHx2ofYvbNqWj3TZV9c/edit?usp=sharing