Manifest destiny was used as a justification for us expansion into the
a)louisiana territory.
b) texas, california, and oregon.
c) british canada.
d)florida, kentucky, and tennessee.

The best option here would be B) Texas, California, and Oregon. Manifest destiny was the belief that it was the American right to expand westward. This is why so many people left the east coast to settle in places like Oklahoma as well as other places. There was lots of land that was availiable for claiming and many saught this allure. B is the answer because it is the only answer that includes things in the West. D is all in the East, A we already had at the time due to the Louisiana Purchase, and C wasn't even apart of the United States. Hope this helped! 

The Correct Answer is B.

"Texas, California, and Oregon"

Explanation:

Manifest Destiny is the belief spread by the many Americans in the mid-1800s that America should expand across the Continent to the Pacific Ocean.The Idea of manifest destiny was the religious Idea which was so common in the speeches and newspapers of that time. Manifest destiny or our faith to settle the land to the Pacific Ocean to spread Democracy is also the President Polk beliefs.