The freedom to assemble protects all of the following except which one?
a. political parties
b. riots
c. marches
d. demonstrations

The answer is letter B. riots.   All groups have the right to assemble to voice out their cause.  Riots, on the hand, are the exceptions.  This is because the intent is to destroy property and threaten the lives of innocent bystanders.  There have been numerous accounts where rioters incite others to commit violent acts that destroy property.  Government will have no choice but to resort force to quell such an assembly.  Apart from the destruction of property and people getting hurt, what cause they want to proclaim gets discredited due to the violent behavior of those in their ranks.

The answer is society was a caste like system with poor whites at the bottom of the white social ladder.