Which issue was addressed by the Supreme Court in the Dred Scott case? A: whether Northerners could own slaves
B: whether Kansas was a slave or free state
C: whether free blacks could vote
D: whether slaves were citizens or property

D. whether slaves were citizens or property

Explanation:

Dred Scott escaped the South and resided in the North, where slavery was prohibited

Supreme Court ruled that slaves are not citizens, and if they are found in the North, they are to be returned to the South as properties

yes, there are senators in each state