What does a journal written by frontier settlers most likely tell you about manifest destiny?
what conditions were like during travels
what settlers thought about “manifest destiny”
when manifest destiny occurred
where manifest destiny took place
where american indians fought for their lands

A journal written by frontier settlers would most likely tell you "what conditions were like during travels" and "where Manifest Destiny took place," since many settlers were not concerned with the more "existential" aspects of the movement. 

what conditions were like during travels

where Manifest Destiny took place

Explanation:

The Manifest Destiny is a phrase and idea that expresses the belief that the United States of America is a nation destined to expand from the Atlantic coasts to the Pacific. This idea is also used by supporters to justify other territorial acquisitions. The supporters of this ideology believe that the expansion is not only good, but also obvious (manifest) and accurate. This ideology could be summarized in the phrase: "By the Divine or God's Authority". The phrase happened to become a doctrine over time.

I believe its D or B if its wrong sorr xD