Answer:
The aspect of the Compromise of 1850 that ignited the most controversy between North and South was:
C. the stricter fugitive slave act.
The Compromise of 1850 was a series of laws that were intended to resolve the territorial and slavery issues that were dividing the North and South. The compromise included provisions for the admission of California as a free state, the establishment of popular sovereignty in New Mexico and Utah, and the outlawing of the slave trade in Washington, D.C.
However, the stricter fugitive slave act was the most controversial aspect of the Compromise of 1850, as it required citizens to assist in the capture and return of runaway slaves, and imposed heavy penalties on those who aided escaped slaves. This was seen as a violation of individual liberties and human rights by abolitionists and many Northerners. The fugitive slave act was also opposed by many African Americans, who feared being captured and returned to slavery.
The fugitive slave act led to a significant increase in tensions between North and South, and was a major factor in the events that led to the American Civil War.