Custom JavaScript verification can be used to implement correct answers like this. Try setting your grid's verification code to this:
// Parameters
var correctAnswers = [1, 2, 1, 2];
var errorMessage = "Wrong answer selected.";
// Run
$('.custom_error_highlighting').removeClass('custom_error_highlighting');
$('input[name="hid_row_list_[% QuestionName() %]"]').val().split(',').forEach(function(row){
if (SSI_GetValue('[% QuestionName() %]_r' + row) != correctAnswers[row - 1]) {
strErrorMessage = errorMessage;
$('#[% QuestionName() %]_r' + row + '_row').addClass('custom_error_highlighting');
$('input[id^="[% QuestionName() %]_r' + row + '_"]').closest('.mobile_grid_card').addClass('custom_error_highlighting');
}
});
Line 2 should be updated with the correct answer for each row. Line 3 can be updated with the error message to show.
That will keep respondents from continuing through the survey. To get the error highlighting you were asking for, please add this to another field in your grid question (footer, HTML header, etc.):
<style>
.custom_error_highlighting {
border: 1px solid red;
}
</style>