如何在optgroup标签中添加^标签

Question

想要在optgroup标签中添加支持脚本..

<select name="ddlSemester">
    <option selected>--Select--</option>
        <optgroup>"11<sup>th</sup>"</optgroup>
            <option>I Sem</option>
            <option>II Sem</option>
        <optgroup label="11"<sup>th</sup>>
            <option>I Sem</option>
            <option>II Sem</option>
        </optgroup>
</select>