How to autofill a field based on a checkbox choice not being selected
I am trying to autofill several fields as not done ([ND]) based on another particular option from a checkbox field being empty. I have tried several ways using calculations that say Case ("field name" not= "option1"; [ND]) but the problem I am having is that although that rule seems to work, it only continues to work if only one of the possible 4 options are selected. So if option 2 or 3 or 4 are selected but not option 1, then the autofill works, but as soon as 2 or more of options 2, 3, and 4 are selected then the autofill stops working. I even tried a very long calculation with every possible combination of selections using the case function (including options 2, 3, and 4 being selected but not 1), and still the autofill doesn't work if more than one option is selected.
Can someone help me write a calculation that autofills a field if option 1 is not selected even if all or none of the other 3 options are selected.