Final answer:
Most accurately, Jefferson Davis would leave and potentially die for Mississippi's rights, aligning with the statement C. Davis and secessionists championed states' rights and were willing to secede to preserve these rights.
Step-by-step explanation:
The statement that most accurately states a claim Davis develops in Paragraph 9 about leaving the Union is C. Though he loves the Union, he would leave it and die to uphold Mississippi’s rights. The key context here points to the strong belief in states' rights and the resolve to defend those rights, even to the point of secession. This aligns with the notion that Far to Jefferson Davis and other secessionists, the legal and moral right to secede was paramount to protecting their state's autonomy and interests, especially in relation to slavery as a cornerstone of those rights.