Which piece of legislation is subject to this cartoon?

a) indian reorganization laws
b) kellogg-briand
c) equal rights amendment
d) immigration quota act

This cartoon is referring to the Immigration Quota Act. This act limited the numbers of immigrants let into the United States to a specific percentage depending on their nationality. This was usually 2 or 3% and did not include those from Asian countries, as they were prevented from immigrating to the United States. 

The value of t is 2