in a line of three possible answers how to prevent multiple answer

[Guest]

I am offering three possible answers to a question. I want to prevent
multiple answers to one question eg. when a cell has been filled I want the
other cells to automatically block

 

[Guest]

You need a worksheet_change event macro. The logic would be something like

Look at all three cells If all three are empty, then unprotect all three.
if any cell is not empty, then protect the other two and unprotect the
non-empty cell.