Which version of AHT for 2009 Mac Pro??

I just got a 2009 Mac Pro off of eBay for a very good price. It did not come with the original discs - I like to have them on hand

in case I need to run the Apple Hardware Test (I don't know why Apple can't make it available to download and burn to a disc).

Can anyone tell me which version of AHT I would need for this machine?? If I find discs on eBay, I need to have the seller

check the AHT version, so that I get the right one. If anyone has any ideas, your input will be greatly appreciated.