What to do if Font Awesome icons are not displayed?

Question

HTML

I have a page where Font awesome is used
When I refer to the icons as

<button id="btn_toogle_header"><i class="fa fa-bars"></i></button>

Everything works, but if like this

<option value="man">I am man <i class="fa fa-mars"></i></option>

It even shows up in Chrome Dev Tools.

Answer 1

https://developer.mozilla.org/ru/docs/Web/HTML/Ele...
<option>

Allowed content - Text, escaped characters (eg é) are allowed.

https://www.w3.org/TR/2011/WD-html5-author-2011080...

Content model: Text.