safe side says #1, but I’d kinda like to take #2 and take Karelia. Then on next round turn right around and throw it all at Belo (which I will assume GER will take) and retreat into Moscow if I don’t have the edge. Depending on what you still hold as USSR, you could hit from places like Lenin, Stalin, Ukr, Turk, Russ, and Mosc itself. Belo is like a big barrel you dump fish into and Ka-boom!
the edge probably will be defined by what GER could bring to Belo on their next turn. If it’s all tanks from Germany, they’ll have to stop in E Poland again and not be able to help what was moved into Belo.
So you effectively took both option 1 and option 2 and made Germany react to what you did and even made them choose what you wanted. Draw them into long supply lines, encircle and crush them.