The federal government responded to the 2001 terrorist attacks on the
World Trade Center and the Pentagon by...

After the September 11, 2001 attacks, the U.S. government responded with immediate action (including rescue operations at the site of the World Trade Center and grounding civilian aircraft), and long-term action, including investigations, legislative changes, military action and restoration projects.

Explanation:

a. because the u.s. was the leading with the most technology, economy, etc. also was teamed with other allies witch boosted the economy and materials to improve technology and use it.

it is

a

asked for and recieved from the united states