title: Rails - disable option in select (based on the condition)
body: <p>I have select:</p>
  
  <pre><code>= f.select(:category_id, @categories, :html_options =&gt; {:class =&gt; 'select_box'}, {:disabled =&gt; true if category.id == 18})
  </code></pre>
  
  <p>The piece of code above obviously returns an error, but how to disable an option according by <code>id</code>?</p>