Answer:
They crossed through Montana and made their way to the Continental Divide via Lemhi Pass where, with Sacagawea's help, they purchased horses from the Shoshone. While there, Sacagawea reunited with her brother Cameahwait, who hadn't seen her since she was kidnapped
I remember the artifact being the Rosetta stone, it had the language that they spoke, Greek, and it had Hieroglyphs.
B, C and D are the correct answers hope I can help!
