Final answer:
The venting of hostility towards innocent Arab-Americans after 9/11 can be best explained by the scapegoat theory.
Step-by-step explanation:
The venting of hostility towards innocent Arab-Americans after 9/11 can be best explained by the scapegoat theory. This theory suggests that when a group of people experiences fear, insecurity, or frustration, they may direct their anger towards a convenient target, in this case, innocent Arab-Americans. This phenomenon is a common response in times of crisis or national trauma.