The correct answer is the following.
At the beginning of the 21st century, most immigrants to the United States came from Mexico and Central America.
Although in the last decade the number of Mexicans has diminished considerably, the number of people from Central America has increased like never before. Specifically, people from Honduras, El Salvador, Nicaragua, and Guatemala had crossed the Mexican border, walk through the Mexican territory until they reach their final destination; the US-Mexico border trying to cross to the United State to ask for an immigration authorization. At this moment, the US-Mexico relationship is tense due to the wave of Central American immigrants that want to enter the United States.