Final answer:
Robespierre was not the king of France during the French Revolution; he was a leader of the Jacobins and associated with the Reign of Terror.
Step-by-step explanation:
The option that does NOT describe Robespierre is D. king of France during the French Revolution. Robespierre was a radical advocate for the republic and led the Jacobins during the French Revolution, but he was never the king. The executed king during the revolution was Louis XVI. Robespierre was known for his leadership during the Reign of Terror, and he indeed was a leader of the Jacobins (A), and was executed in 1794 (C). He was not known as a peaceful negotiator (B), given his association with the bloody Reign of Terror, but since he was not a king, option D is the correct answer.