Question

the department of homeland security was created to
keep noncitizens from entering the united states.
protect the united states from terrorist attacks.
make us citizens more secure in their homes.
strengthen us military presence overseas.

Explanation:

The Department of Homeland Security was established in the aftermath of the 9/11 terrorist attacks, with its core primary mandate focused on safeguarding the U.S. from terrorist threats and related domestic security risks. The other options do not align with its central founding purpose: it does not bar all noncitizens, home security is not its main focus, and it does not handle overseas military presence.

Answer:

protect the United States from terrorist attacks.