The Proclamation Line of 1763 runs roughly along the A. Ohio River. B. Rocky Mountains. C. Mississippi River. D. Appalachian Mountains.

The correct answer is D. Appalachian Mountains.

The Proclamation Line of 1763 was established by the British government following the French and Indian War. It prohibited American colonists from settling west of the Appalachian Mountains to prevent conflicts with Native American tribes. This line aimed to stabilize relations and manage westward expansion. If you need more details or have further questions, feel free to ask or check the extended services page for more in-depth assistance!