PCM Engine DTC 175 Error

[Oskar_PL]

Hello, I’m a happy owner of Nautique 230 MY2016 with PCM EX3 MPI 5.7L 343 HP
One day error DTC 175 popped up. I received the 02 sensor to be replaced. However I have no idea which one should it be. There are two sensors visible on the top of the engine block.
Can anyone help me to locate the right sensor to replace?

Thanks