As a Result of the Great Recession of 2007-2009,illegal Immigration

As a result of the Great Recession of 2007-2009,illegal immigration to the United States:

A) has increased dramatically.
B) fell significantly during the recession but has increased since the recession and the illegal immigrant population is growing significantly again.
C) illegal immigration to the United States fell significantly and the net flow of illegal immigrants following the recession has been close to zero.
D) illegal immigration to the United States fell significantly,and now there is a dramatic backflow that has the total number of illegal immigrants in the United States falling.