Preserve certain tags displays HTML as plain text

In my view, I have a field that has HTML. I don't want the <a> tags (or other HTML tags) to appear in the view, but I do want the <em>, <b>, <strong> and <i> tags.

I clicked "Strip HTML tags". In "Preserve certain tags" I entered <em> <strong> <b> <i>

This works, but now the <em> tags are displayed as the words <em>. They don't get read by the browser as <em> tags. How can I fix this?

Thanks!