After reconstruction, many southern states
a) passed laws forbidding marriage between african-americans and whites
b) urged local business owners to serve people of all races
c) prosecuted the leaders of lynch mob’s
d) required african-american and white voters to use separate voting booths

D) required African-American and white voters to use separate voting booths

Explanation:

After reconstruction, many southern states required African-American and white voters to use separate voting booths.

dirty, contaminated water

contaminated food,

chlostrophobic living spaces,

mice infestation,

etc,

the social contract theory