Final answer:
The correct sentence is 'The economic factors were a key component.' It exemplifies how specific reasons can be the primary cause of historical events, such as the economic crisis triggering the French Revolution and the sweeping changes brought about by the Industrial Revolution.
Step-by-step explanation:
The sentence that contains a word that is used correctly is a) The economic factors were a key component. When discussing historical events and their motivators, it's important to consider the various causes that contribute to the occurrences. For instance, one of the causes of the French Revolution was an economic crisis, which served as a primary cause, affecting the political and social structures of the time.
Regarding the Industrial Revolution, it had massive political and economic impacts, such as the shift from agrarian economies to industrialized ones, leading to urbanization and changes in class structures. Investigating the causes and effects in historical events entails examining how earlier decisions in areas like economy, politics, and society/culture led to significant occurrences like the Great Depression.