In 1857, the Supreme Court ruled in the Dred Scott decision that

A. slavery was inconsistent with the constitution and must be abolished.
B. slavery would be constitutional only in those areas that were already slave territories.
C. protection of slavery was guaranteed in all the territories of the United States.
D. abolition of slavery would be done only in those areas in which it is already abolished.
E. slavery was constitutional, but the slave trade was unconstitutional.