Final answer:
Louis XVI was the king of France before and during the initial stages of the French Revolution, and his reign was troubled by financial crises that contributed to the revolutionary fervor. Therefore, the correct option is b).
Step-by-step explanation:
The king of France before and during part of the French Revolution was Louis XVI. Louis XIV, known as the Sun King, had reigned until 1715, consolidating absolute monarchy in France, but it was his later successor, Louis XVI, who was on the throne when the Revolution commenced in 1789. Louis XVI's reign was marked by financial crises, including the immense debt from Louis XIV's expenditures and France's support of the American Revolution, alongside rising criticism from the Enlightenment. The economic crises and strain on the lower classes contributed to the outbreak of the Revolution. Louis XVI was eventually overthrown during the Revolution and was executed in 1793.
Therefore, the correct option is b).