Your answer is (b) A non citizen in America is know as an alien. It's pretty offensive, but yeah. If you're living illegally in America, then your name is obviously not gonna be listed in the administration in the government, now, is it? XD
"(B)a person living in the United States illegally"
It's basically the same thing as in "Illegal Immigrants" or "Undocumented Immigrants" most likely. So yes, Illegal immigration is the migration of people across national borders in a way that violates the immigration laws of the destination country.
