Why did so many revolutions happen in the late 18th and early 19th century ?

The Age of Revolution is a period from the late 18th to the mid-19th centuries in which a number of significant revolutionary movements occurred in most of Europe and the Americas.The period is noted for the change from absolutist monarchies to representative governments with a written constitution, and the creation of nation states

the answer is a. since they were a huge producer of cotton and wanted the most money for it.