C. Held that federal law controls over state law to the contrary.
Explanation:
Edward Prigg was a slave catcher who abducted Margaret Morgan and her children . Morgan had once been a slave owned by the Ashmore family in Maryland. Pennsylvania then charged and convicted Prigg for violating the anti-kidnapping laws. Then the United States Supreme Court precluded a Pennsylvania state law that prohibited blacks from being taken out of the free state of Pennsylvania into slavery.