Text-aligning CSS not working in Chrome or IE. Yes in FireFox

Question

I try all the different code for center aligning and not work in chrome or IE. Here is my code. I'm trying to align center text in the dropbox. Any suggestion?

  .dropdownmenu,
  .dropdownmenu option 
  {
    text-align:center!important;
  }

  <select class="dropdownmenu" name="memo[How did you hear about us?]" ">
   <option  value="Relativity website">Relativity Website</option>
   <option  value="Internet search">Internet Search</option>
  </select>

Answer 1

In my remember, modify select style is only allowed by Firefox

You can walk around by using a jQuery plugin which simulates a select with div and others tags