Which group of immigrants arriving by boat was processed at ellis island in the 1880s?
-all passengers
-first-class and second-class passengers
-only steerage-class passengers
-third-class and steerage-class passengers
-second-class and third-class passengers

Some information that I found  is that first- and second class passengers did not have to go through the medical inspection on the Ellis island - they were briefly inspected on the ship and it was believed that the prize of their ticket meant they were otherwise not going to have serious medical or legal problems.

So the answer would be: all other classes: which is -third-class and steerage-class passengers