For the second option, to match your screenshot, you would need to place a script like this in the source of a multiple-choice-with-comments question. This script hides some text inputs and renders the question single-choice.
Code:
<script type="text/javascript" charset="utf-8">
$(document).on('ready pjax:scriptcomplete',function(){
var thisQuestion = $('#question{QID}');
// Remove some text inputs
$('.checkbox-text-item:eq(0) .comment-item', thisQuestion).remove();
$('.checkbox-text-item:eq(1) .comment-item', thisQuestion).remove();
$('.checkbox-text-item:last .comment-item', thisQuestion).remove();
// Listener on the checkboxes (exclude all other checkboxes)
$('.checkbox-text-item :checkbox', thisQuestion).on('change', function(e) {
if($(this).is(':checked')) {
$('.checkbox-text-item :checkbox', thisQuestion).not(this).each(function(i) {
$(this).prop('checked', false);
$(this).nextAll('input:hidden').val('');
$(this).closest('li').find('input:text').val('').trigger('keyup');
});
$('input.other-text', thisQuestion).val('').trigger('keyup');
}
});
// Listener on the "Other" input (exclude all other checkboxes)
$('input.other-text', thisQuestion).on('keyup change', function(e) {
if($.trim($(this).val()) != '') {
$('.checkbox-text-item :checkbox', thisQuestion).each(function(i) {
$(this).prop('checked', false);
$(this).nextAll('input:hidden').val('');
$(this).closest('li').find('input:text').val('').trigger('keyup');
});
}
});
});
</script>
