Why didn’t early American railroads actually link different regions to

Why didn’t early American railroads actually link different regions to each other?

a. They did not have enough steel to make the tracks very long.
b. They were only built to bring goods from one city to another.
c. They had different schedules and incompatible gauges.
d. They were only affordable to the richest passengers.
e. They were built with inferior equipment and were constantly breaking down.

ANSWER
C