.Which of the following statements about the Dred Scott decision is correct?
A. It stated that Black people were not citizens of the U.S.
B. Recognized the power of Congress to prohibit slavery in the territories, but refused on technical grounds to free Scott
C. It upheld the constitutionality of the Missouri Compromise
D. It upheld the principle of popular sovereignty
E. It freed Scott, but not other slaves in circumstances similar to Scott's