The correct answer for the question that is being presented above is this one: "B. building of the transcontinental railroad --> disappearance of the frontier." The pair of events that did the first event most directly influence the second is the building of the transcontinental railroad --> disappearance of the frontier.
Don’t u have to list the following?
I believe both lands were targets for major powers such as Britain and France
Answer: its D
Explanation: tundra animals live in cold places they have thick fur to cover them
I believe the answer is A or C