Explain the benefits of the steam engine and the transcontinental railroad

Two benefits of the Transcontinental Railroad System, was that it provided jobs across the nation, for people, and that it sparked markets across the nation, also. I hope that I have helped and not hindered you.  If this has helped, can you please consider marking this answer as the brainliest?  I appreciate it!!!
This was not my answer but someone else's. But here it is.

The answer should be b