Answer:
I think it'd be A, B, and C right?
It would be difficult for the United States for two reasons, the fact that none of the land was mapped other than the areas that previous voyagers had gone through, and the natural landscape of the area, and last, Native American Hostility.
Three examples: When pioneers would voyage to the west, there would often be encounters were they would be attacked by animals that had not been seen before, bears, sneaks, different wolves, and many more. They barely knew the natural resources of the area, such as food, etc.
The next example, no mapping, would be difficult because for the most part, they had no sense of navigation except for the few maps that had been made, even then, would be difficult to navigate.
Native Americans did not appreciate the pioneers coming into the land they considered their own, they resembled hostility and would even kill the civilians that would travel through the land, or capture them.
Hope this helps!! <3
The people because its just that
I say like a blue whale or something like that.
During World War II there were two sides: the Allies, which the US were a part of, which included, among others, UK, France, Soviet Union (after 1941), and the allies (Germany, Japan, Italy and their puppet states).
So the answer can be any of the allies: UK, France, Soviet Union but also the whole of Latin America, most of Africa and Asia.