Answer: People were able to travel from places over land much faster, and it allowed companies to ship resources overland at a large quantity.
Explanation: It can't be the first one since it's pretty clear that it has had a huge impact on peoples' lives. It can't be the second one either because railroads typically cannot go long distances over water. That leaves us with the last option, which should be the only correct answer.
Disclaimer: I didn't research any of this, this is all from my reasoning, but I'm sure this is correct. It's 7:18PM PST when I am writing this, so I hope you can submit that assignment on time.
Hope this helps!