So I was on study island and I came across this question can you please help me out. Here is the passage. Prior to 1869, Americans that wanted to travel from the west coast of the United States to the east coast needed to take a stagecoach or wagon, ride a horse, or walk. By 1853, citizens in the east could take a train from New York to Chicago, and citizens on the west coast could ride a train within California, but there was no railroad across the country. Due to the addition of new states on the west coast (California, Oregon, and Nevada) in the mid-1800s, America needed a faster way to communicate and a better way to ship and trade goods across the country. So, in 1862 Congress passed the Pacific Railroads Act which authorized the building of a railroad across the country: the Transcontinental Railroad.
In order to complete such a massive project, two railways were to be constructed. The Union Pacific would begin construction in the east and work towards the west. The Central Pacific Railroad would begin in the west and work east. The railroads planned to meet in the middle. Since Salt Lake City was such an important center of trade, both railroads wanted their trains to pass through the city. The race was to build the rails as quickly as possible to reach Salt Lake City first.
However, the building of the railroad was not without problems. For instance, the Central Pacific Railroad faced the difficult task of crossing the Rocky Mountains. It was challenging for both companies to find workers. The Union Pacific hired many Civil War veterans while the Central Pacific hired thousands of Chinese immigrants. The construction of the railroad had a negative impact on Native American groups living along the newly constructed railroad. There were often clashes between the railroad groups and the Native Americans.
Despite the huge undertaking and all the difficulties the companies faced, the Transcontinental Railroad was completed on May 10, 1869. This moment was celebrated with a "golden spike" hammered in as the last spike connecting the two railroads, and thus connecting America.

now here is the question
Which sentence provides an accurate summary of the passage?
A.
The United States government was key in the construction of the Transcontinental Railroad.
B.
The Transcontinental Railroad was important for the growth of the United States, both geographically and economically.
C.
The construction of the Transcontinental Railroad was a difficult task that faced many problems during the building process.
D.
The Union Pacific and Central Pacific Railroads were key contributors to the completion of the Transcontinental Railroad.