CodePen Embed - Optgroup

<select>
        <optgroup label="Odd Numbers">
            <option value="1">1</option>
            <option value="3">3</option>
        </optgroup>
        <optgroup label="Even Numbers">
            <option value="2">2</option>
            <option value="3">4</option>
        </optgroup>
    </select>

This Pen is owned by Moises Liria Rosario on CodePen.

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