Answer:
D. People could more quickly and easily travel from coast to coast.
Step-by-step explanation:
Before the Transcontinental railroad travel from the East coast to the West coast was long and hard, the number of people wanting to travel arises when Gold was found in California.
The settlers have several options to travel but they were all with more difficulties than facilities. They could attempt to travel overland but they faced rivers, mountains, and deserts. If instead, they choose to travel by sea they had a six months journey.
To help people with this problem, in 1862 the Federal government enacted the Pacific Railroad Act which tasks the railroads' companies to build a transcontinental one to travel from coast to coast.
I hope this answer helps you.