Final answer:
The measure of social control not implemented by the U.S. government after the September 11th attacks was the internment of Arab Americans. Other measures included enhanced surveillance, citizen reporting of suspicious activities, and increased airport security.
Step-by-step explanation:
c. internment of Arab Americans. This was not a measure of social control implemented by the U.S. government after the September 11th attacks.
In response to these attacks, the U.S. government did enact several measures aimed at preventing future acts of terrorism. The USA PATRIOT Act was passed, allowing warrantless government access to private files (a) and surveillance of individuals under suspicion of terrorist activities. The government also promoted policies for citizens to report any suspicious behavior (b), which expanded the eyes and ears of law enforcement in public spaces. Additionally, airport security was significantly increased (d) to safeguard air travel from terrorist threats.
These actions have been controversial, sparking debates between national security and civil liberties. Despite the government's aggressive stances on security, there was no incident of systematic internment of Arab Americans comparable to the internment of Japanese Americans during World War II, which establishes option (c) as the incorrect answer in this context.