using the timeline detailing an important period in us history to answer the question

Question

missouri compromise 1820> compromise of 1850>kansas-nebraska act 1854>presidential election of 1860
A the implementation of jim crow laws in south
B increasing tensions over tariffs prior to civil war
C the implementation of reconstruction in the south
D increasing tensions over slavery prior to civil war

Answer 1

D increasing tensions over slavery prior to civil war