Based on the article, which statement is true about undocumented immigrants?
a donald trump has argued for loosening security at the u. s.-mexico border.
b president barack obama has attempted to deport all 11 million undocumented immigrants in the u. s.
c the number of undocumented immigrants entering the u. s. has been skyrocketing.
d the number of undocumented immigrants living in the u. s. has not changed much since 2009.