I create an array question. I have 3 questions down the left column and 3 choices across the top row. What I want to do is restrict the response to one choice per answer column and one choice per row. I already have the one choice per row but also want the same for the columns.

I'm wondering if this this possible, and how do I do it?

I think Tony wrote jQuery function which will enforce one choice per column. It's for ranking question I think.

Alternatively, you can also use unique function to enforce that.

have a look here