Which detail best supports the idea that only immigrants with good health were allowed entrance into the united states?

a. one doctor drew chalk marks on immigrants with health problems.
b. the two doctors worked for the united states health service.
c. an h mark on an immigrant meant he or she had heart problems.
d. trachoma is a blinding and very contagious eye disease.

This is an incomplete question. The excerpt in the question is missing.

The answer is --

A. One doctor drew chalk marks on immigrants with health problems  

Explanation:

        The excerpt is taken from Immigrant Kids and is written by Russell Freedman. In the excerpt, two doctors working for the United States Health Department examines the immigrants in the airport for any contagious diseases and health issues and also detain people for any mental problems also.

         In the excerpt, it is given that the doctors mark the immigrants with a chalk those who have some health problems and identify unfit to enter United States.

Thus the correct option is -- (A).

pretty sure a is right