The unanswered question of the Nullification Crisis primarily revolves around 3. Does the federal government or do the states have greater rights and powers?
The Nullification Crisis, which occurred in the early 1830s, centered on the tension between state sovereignty and federal authority, particularly regarding tariffs imposed by the federal government that some states, like South Carolina, deemed unconstitutional. The crisis raised fundamental questions about the balance of power between the federal government and the states, and while it was partially addressed by the outcome of the crisis, it left lingering debates about the extent of state rights versus federal power, which continued to evolve in subsequent years.
Options 1, 2, and 4 pertain to specific aspects of that broader question, but the core issue is rooted in the relative authority of federal versus state powers.