1995 Toyota Avalon oxygen sensor: which is the "bank 1

Autozone scanned the car's computer, and the printout of the code scan indicates P0135 [car is listed as "OEM brand: domestic"---it didn't specify Toyota],scanner interprets the code as "heater condition. Heated oxygen sensor bank 1 sensor 1" But there seems to be some confusion on the internet as to whether this particular model's "sensor 1 on bank 1" is located on the manifold closest to the radiator or closest to the firewall. Can you advise me as to which it is?

Thank you very much!
Bill B