A study of the causes of the American Revolution of 1776, the French Revolution of 1789, and the Russian Revolution of 1917 best supports the generalization that revolution is most likely to occur when

The government doesn't treat its citizens right.

The causes are economic in all three, but famine played a large part in the latter two revolutions. In the Americas, one has to remember also a lot of people in America left Europe because they didn't like it there, ie, they were already fed up. Some states were actually populated with prisoners.

So your answer, I think is Ms Sue's, but I would add to hers "in tough economic times".

Agreed.

there is a combination of political, social, and economic factors that create conditions of discontent and instability.

To arrive at this generalization, researchers would typically conduct a comparative study of the causes leading to these specific revolutions. This would involve analyzing historical documents, primary sources, and scholarly research to identify the common factors that contributed to these events.

In examining the causes of the American Revolution, researchers would likely mention grievances related to British colonial rule, such as taxation without representation, restrictions on trade, and limited rights and liberties. These political factors were intertwined with social and economic issues, including social inequality and economic exploitation, which fueled the desire for independence.

Moving on to the French Revolution, scholars might emphasize the influence of Enlightenment ideas and the growing discontent among the three social estates — the clergy, the nobility, and the commoners. France's political system, characterized by an absolute monarchy and a rigid social hierarchy, contributed to widespread social unrest. Socioeconomic factors, such as food shortages, poverty, and burdensome taxation, added to the revolutionary fervor.

Lastly, in examining the Russian Revolution, factors such as autocratic rule under the Romanov dynasty, a widening gap between the wealthy and the impoverished, and the impact of World War I would likely come to the forefront. These political, social, and economic conditions created a fertile ground for revolutionary sentiments, ultimately leading to the overthrow of the tsarist regime and the rise of communism.

Based on the analysis of these revolutions, the generalization emerges that revolution is most likely to occur when political oppression, social inequality, and economic hardships intersect. When people feel marginalized, deprived of their basic rights, and robbed of economic opportunities, it creates an atmosphere conducive to revolution.

It's important to note that this generalization is not absolute and applies specifically to the cases studied. To make broader conclusions about the likelihood of revolution, further research and analysis of other historical and contemporary events would be necessary.