Read the details from "The Workers of Ellis Island" and think about the central idea they support. Because he was only allowed to admit persons who were "clearly and beyond a doubt entitled to enter the United States," he had to be absolutely certain the person he was examining was not a member of one of the classes of persons barred from entering the country . . . .

Ellis Island doctors were particularly watching for signs of contagious diseases. Incurable diseases included trachoma and tuberculosis and guaranteed a return trip to where the immigrant came from.

Which supporting detail also supports the same central idea?

Throughout the years, numerous organizations offered aid to immigrants at Ellis Island.
Every single foreigner that entered the Port of New York was questioned—either on board ship or at Ellis Island itself.
According to PHS regulations, all nurses visiting New York and New Jersey on their off-duty hours were required to return to Ellis Island no later than the 12:00 a. m. staff boat.
Many interpreters at Ellis Island were either immigrants themselves or the children of immigrants.