The option that explains the trend shown in the table would be B. The passage of the Immigration Act of 1924
The table shows that immigration to the United States from Europe declined sharply after 1924. The Immigration Act of 1924 was a restrictive immigration law that imposed quotas on the number of immigrants from each country.
The law was designed to reduce the number of immigrants from Southern and Eastern Europe, who were seen as less desirable by many Americans at the time.
The Ellis Island immigration facility closed in 1954, but the table shows that immigration had already declined significantly before that.