
In Google Forms, you can use the Checkboxes option to allow the respondent to select multiple options. In a multiple-choice question, respondents can choose exactly one option. Check boxes might look like “Select all…” However, what if the user selects exactly “3” options, no more, no less?
3 points
3 points, more options, menu

Validation of answers
One of the options in the 3-dot menu is Validate Answers. Select this to match the response to specific parameters.

Choose accurately
Default is “Select at least”. Change this to “Choose right”. This will force the user to select option “3”.

Set the number
Enter the number of boxes the respondent should select. It is recommended to set the error text if they select a number other than “3”.

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By using Google Forms, you have more control over how the person responds. With checkboxes, the respondent can select multiple things, but what if you want them to select exactly 3 items, no more, no less? Google Forms Checkbox Forcing Choices is possible.