Read the excerpt from Immigrant Kids, and then answer the question.

But the journey was not yet over. Before they could be admitted to the United States, immigrants had to pass through Ellis Island, which became the nation's chief immigrant processing center in 1892. There they would be questioned and examined. Those who could not pass all the exams would be detained; some would be sent back to Europe. And so their arrival in America was filled with great anxiety. Among the immigrants, Ellis Island was known as "Heartbreak Island."

What best paraphrases the central idea of the excerpt?

Ellis Island was known as “Heartbreak Island” because so many had heart and medical problems while there.
Ellis Island was an important step on the way to American citizenship. Not everyone made it through the examinations.
In 1892, Ellis Island became the nation’s immigrant processing center. Lots of questions and exams were given there.
Immigrants who couldn’t pass examinations felt a lot of anxiety and were sent to live on Ellis Island.