A) They were enacted mostly in the South
Throughout U.S. history, the Southern states were the ones that most opposed the abolition of the institution of slavery and the ones that most prevented African Americas from gaining equality. This is why the Jim Crow laws (that legalized racial segregation) were mostly enacted in the South and were widely accepted there.
The Jim Crow laws were enacted from 1877 through the 1950s, and consisted of a series of restriction on black people, for example, it prohibited them to attend and be in certain places where white people were, such as certain neighborhoods, restrooms, building entrances, elevators, cemeteries, amusement-park, cashier windows, universities, hospitals, jails, etc.