Rack and Pinion - Variable vs w/o

I have a 2012 Buick Enclave and i need to replace the rack and pinion. i went to the auto parts store and they couldnt tell me if i had to purchase the rack and pinion with the variable or without. any help appreciated.

I don't know the RPO code off the top of my head but the quick way to figure it out is to get under and look for a wire going to the rack. If there is a wire it has variable, if there is no wire then it does not.