It's not as trivial in Discover as in Lighthouse Studio, but still possible if you have a subscription. In the select question text area, please click the "Code" button and insert this script:
<script>
$(document).on('ssi_ready', function() {
// Parameters
var correctResponse = 3;
var bigErrorMessage = 'An error has occurred on this page. Please fix this error and try again.';
var smallErrorMessage = 'Incorrect response.';
var verification = function() {
return SSI_GetValue('[% QuestionName() %]') == correctResponse;
};
// Run
var originalNext = $('#next_button');
var clonedNext = originalNext.clone();
clonedNext.attr('id', 'cloned_next_button');
originalNext.hide();
originalNext.after(clonedNext);
clonedNext.click(function() {
if (verification()) {
SSI_SubmitMe();
} else {
var bigError = $('#error_box');
bigError.text(bigErrorMessage);
bigError.removeClass('HideElement').addClass('ShowElement');
$('#[% QuestionName() %]_err').remove();
var smallError = $('<div id="[% QuestionName() %]_err" class="question_error_box error_messages" role="alert"></div>');
smallError.append('<div class="question_errors">' + smallErrorMessage + '</div>');
$('#[% QuestionName() %]_div').prepend(smallError);
}
});
});
</script>
<style>
#cloned_next_button {
color: white;
font-size: 16px;
border: none;
border-radius: 4px;
outline: none;
}
</style>
Line 4 should be updated with the correct answer. Lines 5 and 6 can be adjusted with the error text that will be shown.