I cant believe you took apart everything and also under took a task of changing the water pump and now you you are asking which one is the bottom coolant hose.
I hope you are not kidding us. - Just like that kid the other day on this forum.

Anyway for your future projects no matter how good your memory is , draw a rough diagram of locations of each tube and hoses. That way you are not lost when putting things back. Also from my experience of changing a carburator in 1985 oldsmobile, I can tell yoy that taking a video clip of all attachments etc before and while you are taking aparts things is very very helpful.
Dont get me wrong I think most of us have been there. I am also not challenging you ability or memory. This is just a little thing that my brother told me when we used to fix his scooter and motorcycles years back.

MVK

__________________
One penny saved is three penny earned.

1985 300D Turbo 179,000miles