Answer: d. was based upon a broad and flexible interpretation of the Constitution.
Step-by-step explanation:
The South were heavy proponents of slavery and they resented the Federal government's efforts to reduce its occurrence. This feeling of discontent kept growing until it became quite extremist.
These extremists felt that the Federal government should not be able to impede upon the rights of states and so favored a broad and flexible interpretation of the Constitution that would support their rights as states and make them get away with slavery.