Dred Scott had been enslaved for many years in Missouri. Later, he moved with his owner, who was an army surgeon, to Illinois and then to the Wisconsin Territory, where slavery was not allowed. After they returned to Missouri, Scott's owner died. The owner's wife took ownership of Scott, and eventually those rights transferred to her brother, John Sanford. Antislavery lawyers helped Scott to file a lawsuit, a legal case brought to settle a dispute between people or groups. Scott's lawyers argued that, because Scott had lived in a free territory, he had become a free man. According to Dred Scott's lawsuit, how had his rights been violated?

A. He had been forced to move against his will to different places.
B. He was not not allowed to talk to a lawyer to prepare for his case.
C. He was kept as a slave although he had lived in free territory.
D. His ownership had been transferred without his agreement.