The main reason the French and Indian War broke out was that The French built forts to stop the English from settling on land around the Ohio River.
The French and Indian War:
The French did this to limit British expansion into the area around the Ohio River and instead to led to a series of conflicts that culminated in the Battle of Fort Necessity that then led to war.
In conclusion, option D is correct.
Find out more on the causes of French and Indian War at https://brainly.com/question/9134043.