Many arab americans face especially after 9/11.
racism
segregation
islamophobia
prejudice

The correct answer is: "islamophobia".

Islamophobia is defined as the hate, fear or discrimination against Muslims due to their religion and specially, when these are regarded as a geopolitical power.

The 9/11 attacks perpetrated in 2001 by Al Qaeda, an extreme Muslim group, increased the incidence of this islamophobia phenomenon.

an informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.