Final answer:
Option B.
The Rocky Mountains present a major geographic barrier to movement from Washington, DC, to California.
Step-by-step explanation:
Movement from Washington, DC, to California would be inhibited by the Rocky Mountains, which are a major geographic barrier. The Appalachian Mountains are on the east coast and would not be a barrier for westward movement.
The Great Plains present no significant barrier to travel, and the Mississippi River, while a substantial water feature, has many bridges and is not a significant barrier to cross-country travel today.
The Rocky Mountains stretch from the northernmost part of British Columbia, in Canada, to New Mexico, in the southwestern United States.
For settlers in history, such as those traveling on the Oregon Trail, and even for travelers today, the Rockies present a substantial physical challenge due to their height, rugged terrain, and the high mountain passes that must be crossed.
Please mention the correct option in the final answer: b) Rocky Mountains.
Final Answer in 20 words
The geographic barrier inhibiting movement from Washington, DC, to California is the b) Rocky Mountains.