You get one month to prepare. For the geese, you only can use your bare hands and all three will come at you at the same time. For the bear, you can use any one weapon invented before 500 AC.
You receive $100,000 for each goose killed, or $10,000,000 if you kill the bear.
I’d bail. Pick the bear, do my best to make a very big publicity stunt around it, then go to the betting offices. I’d tell everyone I cared about to go all in on me bailing and to give me some proceeds, and then bail. I dunno how much money this would generate, but at least I get something out of not fighting