<script type="text/javascript">
    $(function () {
        //MultiChoice Field static name
        $('input', 'table[id^="MultiChoice"]').each(function () {
            $(this).change(function () {
                if (this.checked) {
                    //Option  field title
                    $('nobr:contains("Option")').closest('tr').hide();
                } else {
                    $('nobr:contains("Option")').closest('tr').show();
                }
            });
        })
    })
</script>