Specify NUnit as Test Tool in Build Step

     Hi,
I'm completely new to TeamCity (just saying for incase my questions are stupid.  :-) )

Doing a walkthrough (PluralSight) and in the tutorial the guy edit an build step where there are an option to specify you are using NUnit.

I guess he's using and older version (I have whatever was the latest 2 weeks ago) because in mine there are no such option.
(Only have .Net Coverage Tool, but no checkbox like in the video for specifying NUnit being used)

Am I missing something obvious?