title: Adding html class tag under <option> in Html.DropDownList
body: <p>I've been looking for answers on how to add an HTML class tag on my html.dropdownlist. here is the code</p>
  
  <pre><code>&lt;%: Html.DropDownList("PackageId", new SelectList(ViewData["Packages"] as IEnumerable, "PackageId", "Name", Model.PackageId))%&gt;
  </code></pre>
  
  <p>I want to add classes for options under the select element so that I can use this chained select :</p>
  
  <pre><code>&lt;select id="category"&gt;
    &lt;option value="1"&gt;One&lt;/option&gt;
    &lt;option value="2"&gt;Two&lt;/option&gt;
  &lt;/select&gt;
  &lt;select id="package"&gt;
    &lt;option value="1" class="1"&gt;One - package1&lt;/option&gt;
    &lt;option value="2" class="1"&gt;One - package2&lt;/option&gt;
    &lt;option value="3" class="2"&gt;Two - package1&lt;/option&gt;
    &lt;option value="4" class="2"&gt;Two - package2&lt;/option&gt;
  &lt;/select&gt;
  
  $("#series").chained("#mark");
  </code></pre>