No worries, I understand that

I can't guarantee this will work because I haven't done it, but it should. Just backup first of course.
Open up /skin1/help/contactus.tpl
Use code similar to this, substituting language, etc. and place it where in the html you want it to appear.
Code:
<tr valign=middle>
<td class=FormButton>What option best describes you?:</td>
<td><font class=Star>*</font></td>
<td nowrap>
<select name=describeself class="form">
<option value=""{if $userinfo.describeself eq "" AND $describeself eq ""} selected{/if}>Please Select an Option</option>
<option{if $userinfo.describeself eq "Option A"} selected{/if}>Option A</option>
<option{if $userinfo.describeself eq "Option B"} selected{/if}>Option B</option>
<option{if $userinfo.describeself eq "Option C"} selected{/if}>Option C</option>
</select>
{if $fillerror ne "" and $userinfo.describeself eq ""}<font class=Star><<</font>{/if}
</td>
</tr>
Only include these 2 lines if you want it mandatory:
Code:
<font class=Star>*</font>
{if $fillerror ne "" and $userinfo.describeself eq ""}<font class=Star><<</font>{/if}
If you want it mandatory open include/help.php and find:
Code:
$fillerror = (empty($contact["firstname"]) || empty($contact["lastname"]) || empty($contact["email"]) || empty($contact["subject"]) || empty($contact["body"]));
And replace with:
Code:
$fillerror = (empty($contact["firstname"]) || empty($contact["lastname"]) || empty($contact["email"]) || empty($contact["subject"]) || empty($contact["body"]) || empty($contact["describeself"]));
Open /skin1/mail/help_contactus.tpl
Where you want the info to appear put (create language variables if you want):
Described self as: {$contact.describeself}