d audio description in SMIL 1.0... &lt;/option&gt;
    &lt;option value="SM2"&gt;SM2: Adding extended audio description in SMIL 2.0... &lt;/option&gt;
    &lt;option value="SM6"&gt;SM6: Providing audio description in SMIL 1.0... &lt;/option&gt;
  &lt;/optgroup&gt;
  &lt;optgroup label="ARIA Techniques"&gt;
    &lt;option value="ARIA1"&gt;ARIA1: Using WAI-ARIA describedby... &lt;/option&gt;
    &lt;option value="ARIA2"&gt;ARIA2: Identifying required fields with the "required"... &lt;/option&gt;
    &lt;optio