Cannot add attribute on options of select box

hi guys,

Im having hard tim in figuring on how to add the attribute "id" on each option in my select box? here is my code.

<?php

self::$registration_form['select'] = new Select('select',   
        [   //select value
            'male' => ['id' => 'opt1'],
            'female' => ['id' => 'opt1']
        ], 
        [   //select class,id
            'class' => 'form-control gender',
            'id'    => 'gender'
        ]
  );

it gives me the output

<select id="gender" name="select" class="form-control gender">
    <optgroup label="male">
    <option value="id">opt1</option>
    </optgroup>
    <optgroup label="female">
    <option value="id">opt1</option>
    </optgroup>
</select>