In 1933 congress repealed prohibition with the what?

What would lead a historian to consider two events to have a relationship of correlation rather than causation

How did the invention of the cotton gin affect slave labor in the united states? a. there was a forced migration of slaves from the south to the north. b. slave-owning cotton planters were gradually forced to sell their plantations. c. more slaves were purchased to work on cotton plantations in the south. d. the reduced need for labor on cotton plantations led to a decline in slavery. e. slaves were moved from cotton plantations to sugar plantations.

How are the republican and democratic presidential candidates chosen? a. they are nominated by their state governments. b. each is nominated by his or her respective party. c. each is chosen by the governor of his or her home state. d. they are chosen by the house of representatives.