I have questions which give you the option to select tick boxes, but have noticed that a delegate has picked 2 options against the same question. Can you restrict the survey in some way for them to only pick one option?
The checkbox question is specifically designed to allow respondents to select multiple answer options.
If your survey is already collecting data, the best option is to edit the questions and use the ‘Max Answers Selectable‘ setting under the question’s Validation tab to limit answers to 1:
In the future, I recommend using the Radio Button question as this question type is specifically designed to collect only one answer:
I hope this helps clarify!