O2 sensor part #

[jscribn1]

I need to replace my Bank 1 Sensor 2 O2 sensor and need some help with which one this is? I know it's on the passenger side but which one? Closest to the firewall or further back towards the back? To keep it easy front or back? Also looking on Rock Auto to replace it, which one is it on there? A lot of part #'s with no explanation as to which one it is. Any help is appreciated, this is my first repair at something like this.

 

[spadesluck]

Sensor 2 is after the cat, furthest away from the engine.