B. It marked the official beginning of the French Revolution
Why:
"Traditionally, this fortress was used by French kings to imprison subjects that didn't agree with them politically, making the Bastille a representation of the oppressive nature of the monarchy. This event was the start of the French Revolution and the eventual fall of the French monarchy." -https://www.historyonthenet.com/why-was-the-storming-of-the-bastille-important/
