I am trying to custom validation for a matrix where only one answer in possible in the table, but I cannot find a solution for it.In my example attached you can see that there possible to give several answers. But only one combination is possible, not five as displayed.
I am attaching the format that I am using. I am also flexible to try other options. 
Thank you in advanced for your ideas.
Solved
I would like to know how to enforce a single answer in matrix likert type?
Best answer by MatthewM
In that case, I just remembered that you can arrange multiple choice single answer questions in columns, so I think this might be your best option:

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A better option would be either to add a "Not applicable" column that the respondent would select for the rows that do not apply, or use a drop-down question instead and merge the row and column options together so you have 25 options: "Situational: less than 20%", "Situational: 20-40%", etc.