Final answer:
Manifest Destiny is a belief that the United States had the right to expand across the continent.
Step-by-step explanation:
Manifest Destiny was a concept in American history that referred to the belief that the United States was destined to expand its territory across the North American continent. The correct answer to the given question is A. The statement that best defines the concept of Manifest Destiny is: The people of the United States are entitled to expand across the continent. This belief influenced the westward expansion of the United States in the 19th century, leading to territorial acquisitions such as the Louisiana Purchase, the Mexican-American War, and the annexation of Texas.
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