Why Was Charles-Maurice De Talleyrand a Significant Figure During Napoleon's

Why was Charles-Maurice de Talleyrand a significant figure during Napoleon's reign?

A) His loyalty as an adviser to Napoleon was unwavering and enabled the emperor to remain in power years longer than he would have otherwise.
B) While serving as foreign minister, he secretly plotted with French allies to end Napoleon's claim to the throne.
C) He introduced a series of major reforms in France on Napoleon's behalf, including the end of the "department" system.
D) He was a French military general who helped implement the use of new technology on the battlefield.
E) He was a French painter whose works glorified the idea of an endless expansion of the French Empire.