Nexus Root Toolkit question

[miseryguts]

I've got a 16GB Nexus 7 I wish to root on 4.1.1
The toolkit has several different 4.1.1 options to choose from:

NAKASI: Android 4.4.1 - Build JRO03C (Jelly Bean)
NAKASI: Android 4.4.1 - Build JRO03D (Jelly Bean)
NAKASI: Android *** - Any Build

Which one do I choose..?

Thanks.