2. After September 11, 2001, the USA Patriot Act increased the authority of the U. S. government to-
A. Forcibly relocate suspected terrorists and their
families
B. Declare war against international terrorist groups
C. Investigate people in order to prevent or stop
terrorist attacks
D. Establish military bases in foreign countries to
monitor terrorist activities

C.

Explanation:

The USA PATRIOT Act is an abbreviation for 'Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism.' The Act was enacted in the Constitution after September 11, 2001, attack in America. The purpose of this act was to prevent any terrorist attacks or activities and to protect the citizens. The act was signed into law by President George Washington Bush on 26th October 2001.

After the act has come into pass, it has helped to combat and prevent many terrorist attacks  on America. This act has helped to bring many successful operations.

Thus the correct answer is option C.

c. as a force against soviet invasion of afghanistan