TinyMCE closing incorrectly

I’m trying to put in a simple form that has a <select> with multiple <option> statements. For some reason when I go to visual editor after writting the html, there is inserted a <select> </select> around every <option>. Obviously this doesn’t work to create a dropdown select list. Any ideas of why this is happening and what to do?

This is the code snippet from the html editor:

<table>
<tr><td><input type="hidden" name="on0" value="Support levels">Support levels</td></tr><tr><td>
    <select name="os0">
	<option value="Option 1">Option 1 : $5.00USD - monthly</option>
	<option value="Option 2">Option 2 : $3.00USD - monthly</option>
	<option value="Option 3">Option 3 : $1.00USD - monthly</option>
    </select>
</td></tr>
</table>

And this is the result after going into the visual editor:

<table>
        <tbody>
            <tr>
                <td>
                    <input type="hidden" name="on0" value="Support levels" />
                    Support levels
                </td>
            </tr>
            <tr>
                <td>
                    <select name="os0">
                        <option value="Option 1">
                            Option 1 : $5.00USD - monthly
                        </option>
                    </select>
                    <select name="os0">
                        <option value="Option 2">
                            Option 2 : $3.00USD - monthly
                        </option>
                    </select>
                    <select name="os0">
                        <option value="Option 3">
                            Option 3 : $1.00USD - monthly
                        </option>
                    </select>
                </td>
            </tr>
        </tbody>
    </table>