What group was directly responsible for the terrorist attacks on the united states on september 11, 2001 ?

a. al qaeda
b. the taliban
c. afghanistan rebels
d. saudi arabians

The group that was directly responsible for the terrorist attacks on the United States on September 11, 2001 is known as A. al Qaeda, which in Arabic means "The Base," or "The Foundation." The group was led by Osama bin Laden until his murder in 2011. 

The answer is c. hope that