Final answer:
The Treaty of Utrecht established clear territorial boundaries and shifted control among European powers, notably enhancing British influence in North America.
Step-by-step explanation:
The Treaty of Utrecht in 1713 significantly affected relations in North America among European powers. The correct answer to the student's question is C) It established clear territorial boundaries and shifted control among European powers. By the terms of the treaty, Queen Anne secured more territory in North America for Britain, including Acadia and Newfoundland, and rights to the Atlantic slave trade for thirty years. This agreement confirmed Britain's rising power, while France and Spain's influence waned. The British conquest of Acadia, weakening of Spanish Florida, and a focus on maritime commerce over territorial acquisition in Europe, set the stage for future conflicts such as King George's War and the French and Indian War. These changes emphasized the importance of strengthening British colonies in America.