Answer:
The correct answer is D. What caused the abolishment of the French monarchy was the transformation of France into a democratic republic.
Explanation:
Louis XVI recognized the need for rigorous reforms, as advocated by countless people in the decades before, including the great thinkers of the Enlightenment. Not only did the economy need to recover, the freedom and equality of ordinary people had to be promoted.
None of the finance ministers achieved much, mainly because of opposition from the nobility, including the queen herself, who, unlike her husband, was hated by the people. After unrest in the summer of 1789, the French Revolution broke out and major political changes followed, which went too far for Louis. Many nobles then left France and in the winter of 1790-91, and even Louis conceived the same plan. In June of that year, Louis and his family fled incognito, but at the town of Varennes-en-Argonne they were captured by the revolutionaries.
On September 3, 1791, the absolute monarchy was replaced by a constitutional monarchy. The Kingdom of France was renamed the "Kingdom of the French". This period did not last long; on September 21, 1792, the monarchy was completely abolished and replaced by the First French Republic.
On August 10, 1792, the king was placed under house arrest. In December of that year, he had to answer to his actions before the National Convention. On January 16 and 17, 1793, the Convention voted in favor of the death penalty, which was executed on the 21st with the guillotine.