The borderlands of the Southwesta. had only rarely been a source of tension for Americans since the passage of the Hart-Celler Act. b.emerged as an area of renewed anxiety for some Americans in the wake of the September 11 attacks. c.only infrequently enjoyed close cultural and community connections to Mexico. d.seemed less of a national security threat than the borderlands of the Pacific Northwest. e.were not largely affected by the September 11 attacks because of their location.

B. Emerged as an area of renewed anxiety for some Americans in the wake of the September 11 attacks.

Explanation:

The United States government adopted actions to improve its response to terrorism after 9/11. In the borderlands of the Southwest, Americans got anxious and insecure because of the terrorist attack. Efforts were done to restore a sense of security after the attack on the World Trade Center. The World Trade Center attack on September 11, 2001, where 2,977 people were killed.