What are some barriers to development for countries?

Toward the end of the roman empire, what caused a decrease in the use of coined money tell me now

How did the mountains on the oregon trail influence the timing of pioneers’ travels? a.) the pioneers wanted to avoid times when there was snow in the mountains. the pioneers wanted to spend as much time as possible enjoying the mountain scenery. b.) the pioneers crossed the mountains in late fall when the trees were bare and the views were good. c.) the pioneers were rugged people who were not impacted by the terrain they crossed at any time.

Einar sees alexandra every day across the room in his history class but has never talked with her. einar likes the way alexandra looks, including the way she dresses and how she wears her hair. he's even more attracted to her apparent intelligence and the way she handles herself in class discussions and during interactions with the instructor. he'd like to know more about her, so he asks one of his friends about her. einar, using a passive strategy to gain information about her, is probably in the preinteraction awareness stage of any relationship that might develop between them. t/f