This is an impressive spreadsheet, and it is evidence of wonderful work in the community. It's a privilege to be able to help even in this little way.
The problem (I believe) is that the Data Validation was set up by entering the actual list of acceptable answers into the DataValidation dialog box. It looked like this when you opened it up:
That's a perfectly valid way to do Data Validation, but it is harder to edit, harder to maintain, harder to extend....all sorts of "harder's"!
I still use a list, but I've found over time that a much more flexible way to have a list for data validation purposes is to create a separate sheet altogether--where other "reference tables" can be posted as well, other data validation tables perhaps (although I am surprised to see that you don't appear to have DataValidation rules set for any of the other columns). That other way to use a list is to create the list at a place in the workbook where it can sit undisturbed and out-of-the-way (usually a distinct sheet solely for that purpose. And then just type the list in a column, as you'll see in this revised version of what you sent me.
The new tab at the very left contains that table (you can move it if you wish). Then we now are able to have a DataValidation dialog box that looks like this:
What this enables is a number of things:
- let's assume you want to change one that you never use, or just clarify the wording: all you need to do is change the table...no need to open the data validation dialog and re-apply it to all the affected cells
- let's assume you want to remove one of the choices: just remove it. If you delete the row, the reference in that dialog box will automatically adjust (however, be careful with that method if you've created other reference tables off to the side in those same rows)
- let's assume you want to ADD a choice: just add it, and then, yes, you'll need to go into the DataValidation dialog and extend range of cells referred to; after that, with one additional row, it will read =RefTables!$A$1:$A$8
There is another way to do the reference--using Excel's Named Range capability. That actually makes it even easier...but I'll let you research that on your own. If you want, come back and ask about it.