Final answer:
The Treaty of Paris resulted in Great Britain losing all of its colonies in North America.
Step-by-step explanation:
The Treaty of Paris marked the end of the American Revolutionary War and was signed in 1783. The major effect of this treaty was that Great Britain recognized the independence of the United States and officially ended its control over the American colonies. So, option A - Great Britain loses all of its colonies in North America is the correct effect.
Learn more about The impact of the Treaty of Paris on British colonies in North America.