The belief behind Manifest Destiny was that it was the United States' divine right and destiny to expand its territory across the North American continent. Therefore, the response that aligns most closely with this idea is:
Native Americans would benefit from the introduction of the settlers’ American way of life.
This reflects the belief held by many settlers during that time that their civilization and way of life would be superior and beneficial to those they encountered, including Native Americans, which underpinned much of the justification for westward expansion.